Their most recent research was on goldenrods, the Solidago genus. This is a group with a bit of a jagged reputation. They’re falsely blamed for causing allergies. (Their pollen spreads on bees, not the wind.) They’re keystone species because of their immense value to wildlife. They’re perceived as weedy and aggressive. A couple of species are quite ambitious. Canada goldenrod and smooth goldenrod, for example, are genuine problems in Europe. But there are more than 100 species in this genus, most of which are perfectly “polite” in the garden.

Various gardening podcasts and articles have covered the “top performing”1 goldenrods in the trial. That is, the ones that looked good, bloomed prolifically, resisted disease, etc. But I’m going to focus on the trial’s data on insect interaction. I want to know which goldenrods might conjure the coolest and most interesting bugs to run after and make the subject of clumsy, blurry photographs.

Alternatively, if you’re not into bugs, then which goldenrods will conjure the most food for cool and interesting birds. Hummingbirds, for example, need protein, and they can’t get it from the red plastic feeder. They eat ants, mosquitoes, weevils. They even raid spiderwebs—both for the spider’s meal and the spider. So in a way, a goldenrod is a hummingbird feeder.

The top goldenrods by wildlife

The trial data comes from regular observations of 70 goldenrods between May and November over 3 years. A researcher would go stare at a cluster of flowers for 60 seconds and write down what they saw. From this, they extracted a couple of metrics:

• Average insects per observation: The total number of insects they saw divided by the total number of observations.

• Total bumble bee observations: Raw count of bumble bees over the course of the observations.2

One caveat. Mt. Cuba describes the trial as happening in “full sun in ‘average’ garden soil best described as a clay-loam with a pH near 6.5.” And it’s in Delaware, in zone 7a. So the conditions here might not be perfect for a forest-dwelling goldenrod more at home in northern Maine.

Still, the results are interesting, and competition is fun. So in this post, I’m going to report on the top goldenrods across these two metrics, average insects and bees.

Note: I’m leaving one species, Sand or Locust Fork goldenrod (Solidago arenicola) out, even though it wiped the floor with the competition as far as bumble bee visits go. It has a small, very specific native range, and doesn’t seem like something you’d be able to easily purchase seeds for, anyway.

Leavenworth’s goldenrod (Solidago leavenworthii)

• Insects per observation: 12.37 (1st place)

• Bumble bee observations: 74 (4th place, tied)

I must emphasize how much this plant won the “insects per observations” category. The average insects across trial plants was 3.3 per observation. That’s actually pretty good. Go look at a flower in your garden for a minute, and you might not see 3 insects. But Leavenworth’s goldenrod averaged 12.37 per observation!

A few things might’ve contributed to this. First, it’s a very large plant, the largest in the trial, with a huge number of flowers, perhaps as many as 350. It also bloomed late in the year in Delaware, October and November. Perhaps it was the main thing available, even as many insects were beginning to pack it in for the winter.

Mt. Cuba assigned it a score of 3.5 because its foliage tended to flop. One tool we sometimes use to prevent floppiness is the so-called Chelsea chop, where you cut a plant back by about a third to keep it shorter and neater. Unfortunately, Leavenworth’s probably isn’t a candidate for this, since it already blooms late. Chelsea chopping delays flowering. In this case, it might delay it until after most pollinators can use it.

Leavenworth’s goldenrod is native to the southeastern U.S. north to the mid-Atlantic. It lives in bogs and along coastal plains. (A coastal plain is flat, low elevation land near the coast.)

See Mt. Cuba’s summary for Leavenworth’s goldenrod.

Facts for gardeners

• Height: About 8 feet

• Moisture: Native to wet and boggy soils, but Mt. Cuba’s data says it’s also fine in dryer soils.

• Sun: Full sun, not shade tolerant.

• Bloomed in Delaware: Late fall, October through November in Delaware.

• How it spreads: Ambitiously, even aggressively, through rhizomes. Will create large drifts. (Seeds also spread in wind.)

Editorial note: Might look good alongside Joe Pye or ironweed, especially in a larger space.

Riddell’s flat-top goldenrod (Solidago riddellii or Oligoneuron riddellii)

Note: I included the second latin name because I saw at least one well-known seed seller using it. The reason there are two latin names is that taxonomists are having an argument that’s at once perfectly reasonable and annoying to those of us who like to think latin names are stable.

• Insects per observation: 9.15 (2nd place)

• Bumble bee observations: 86 (3rd place)

This plant was an insect favorite. Its overall score was only 3.7, a little lower than the top plants because it had a tendency to flop. 3

However, to be fair to other species that “performed worse,” this plant really benefits from the way Mt. Cuba collects data. Riddell’s only blooms for a couple weeks. This means all of its flowers open basically at the same time—and it may have around 450 flowers per plant.

Mt. Cuba measures insect visits per 60 seconds. If all of your flowers are open at once, you’re likely to get more in 60 seconds than if you bloom over a long period of time, and only some of your flowers are open. (This makes Leavenworth’s goldenrod, which blooms over a couple months, even more impressive to me!).

That said, it also benefits from its flower structure. Like a few other goldenrods, Riddell’s has flat-topped corymbs, essentially a flat landing pad made of flowers.4 This makes flower access potentially easier than the wands and spikes other goldenrods feature.

This is a midwestern species that lives in wet meadows and near waterways. Think “sunny rain garden,” right next to your irises.

Mt. Cuba’s summary of Riddell’s goldenrod.

Facts for gardeners

• Height: About 5 feet

• Moisture: Wants moist soil, though it did well in the “average” conditions of Mt. Cuba’s trial garden.

• Sun: Full sun, not shade tolerant

• Bloomed in Delaware: September

• How it spreads: Seeds spread in wind. Also has short rhizomes that let it form “well-behaved” clumps.

Atlantic goldenrod (Solidago arguta)

Other common names for this species include forest goldenrod and cut-leaf goldenrod.

• Insects per observation: 7.25 (3rd)

• Bumble bee observations: 74 (4th place, tied)

This goldenrod would’ve preferred the dappled light of a forest edge to the full sun of the trial garden. It nevertheless did extremely well—at least as far as feeding the insects goes. A last factor might be because it bloomed basically all fall, late August to late October.

Solidago arguta has a flower structure that could also be a great band name: pyramidal plumes. In botany, this name refers to a structure where a central stem supports a tower of flowering stems that’s widest at the bottom. Some plume-creating flowers, like Solidago arguta, only create flowers along the upper part of the stems, instead of all around. This is called a pyramidal secund (with a “u”) plume.

This plant is normally found near forests across the eastern U.S. and into Canada. Its overall score was 3.5. Mt. Cuba reported that its “stems tended to flop and the foliage was affected by lace bug and powdery mildew,” but also that it might’ve done better “if provided some shade and drier soils.”

Mt. Cuba Center’s summary of Atlantic goldenrod.

Facts for gardeners

• Height: Mt. Cuba says 5.5 to 7.5 feet. Possibly much shorter (2-3 feet) in the shadier habitats it typically grows in, though.

• Sun: Very shade tolerant. May have suffered appearance wise a little in full sun (though Mt. Cuba suggests the issue may actually have been moisture.)

• Bloomed in Delaware: Late August to late October.

• Moisture: Prefers dryer soils.

• How it spreads: Seeds spread in wind. Also has short rhizomes that let it form “well-behaved” clumps.

Mountain goldenrod (Solidago curtisii)

Note: In researching for this piece, I stumbled on another species, Solidago flaccidifolia, that’s so similar to this one that they might just be varieties of each other. And its common names are mountain goldenrod or mountain decumbent goldenrod.

• Insects per observation: 6.58 (4th place)

• Bumble bee observations: 118 (2nd place)

This was the 4th highest insect count in the trial. It was 2nd for bumble bees—and by a lot.

This goldenrod’s associated with the southern portion of the Appalachian Mountains. It’s native through the mountainous southeastern U.S. as far north as the mid-Atlantic states (e.g. Pennsylvania, Delaware). It’s a woodland plant, at home in the shady understory, though it apparently also did very well in the full sun conditions of the trial. Mt. Cuba assigned it a trial score of 3.9, in the top 20% of species.

Mt. Cuba Center’s summary of mountain goldenrod.

Facts for gardeners

• Height: Mt. Cuba says about 6 feet. However, this is another case where it might grow much shorter, e.g. 1-3 feet, with shade.

• Sun: Can handle both full sun and a lot of shade.

• Bloomed in Delaware: September to October.

• Moisture: Not too wet. Think, “Lives in the dry, shady understory of a mountain forest.”

• How it spreads: Seeds spread in wind. Also has short rhizomes that let it form “well-behaved” clumps.

Showy goldenrod (Solidago speciosa)

• Insects per observation: 6.05 (8th place, tied)

• Bumble bee observations: 51 (8th place)

This species didn’t do as well as the others I’m writing about, and Mt. Cuba only assigned it a 3.4 overall (for floppy stems and a poor floral display). However, it’s more promising than it looks. The average insects score of plants 4th-9th was, on average, 6.32—only slightly higher than this one. And Mt. Cuba’s own analysis is that it would do better in rockier, dryer soils. In its home habitat, it’s a pretty stunning plant.

Showy goldenrod is native basically across the entire eastern half of the U.S. It’s found in sandy prairies and dry open fields.

Mt. Cuba Center’s summary of showy goldenrod.

Facts for gardeners

• Height: About 5 feet

• Sun: Full. Not shade tolerant

• Bloomed in Delaware: mid September through late October. Pretty impressive!

• Moisture: Prefers dry soil.

• How it spreads: Seeds spread in wind.Also has short rhizomes that create clumps.

Iris people have decided, for whatever reason, that there’s not enough jargon in botany, and they need to come up with their own. Admittedly, theirs is cooler. For example, instead of sepals and petals, they talk about falls and standards. Throughout this piece, I’ll write the “normal” botanical word first and the Iris Talk word second, e.g. "sepals (falls).”

What it looks like

Northern blue flag is about two or three feet tall from its base to the top of its flowers. A mature clump may send up four or five blooms, usually not at the same time.1 It’s a solidly medium-sized iris, though smaller than the hulks commonly sold at nurseries, such as Siberian irises and bearded irises. Still, it holds its own in the area most people come to irises for, the flowers.

Iris flowers are the muscle cars of the gardening world: they’re loud, colorful, and run out of gas kind of quickly. My blue flags, for example, flower in late May and finish up in June. They’re mostly purple with deep purple veins and three yellow signal blazes, or signals.

Northern blue flag flowers are not subtle. Here are the major pieces, which sit on top of each other like an interlocking layer cake.

• Three large, drooping sepals (falls) that end in yellow signals. The signal isn’t just for you. It’s also a landing strip for bees.

• Three rounded, lightly veined petals (standards) sit in the gaps between sepals.

• Three rectangular style arms hover over the sepals. These are actually modified pistils, the female reproductive part of a flower.

The purple veining persists through the signal, which is one of the cool and distinguishing features of this species. Supposedly this helps you distinguish it from southern blue flag. However, there are lots of research grade observations on iNaturalist where the southern species also has heavy purple veining.

Iris leaves, including Iris versicolor’s, are one of the defining features of the family they belong to, Iridaceae. They’re long, narrow, pointed, and often described as “swordlike.” Unnecessarily, there are 2 technical terms for this structure: ensiform or gladiate. Ensiform is from the Latin ensisformis, or sword shape. Gladiate comes from gladius, or sword. They also spread out in a fan from the base.

A bizarre feature of iris leaves is that they’re folded in half, like someone’s begun a paper airplane. This is easiest to see at the base, where the fold is open enough to clasp the stem. As you move up the leaves, though, they fuse together. This means you are always looking at the lower side of the leaf (the abaxial side). The upper leaf (adaxial side) is enclosed in the fold.

Where it lives

Habitat

This is a plant that lives for summer vacation: wet feet and sun and acidic, rich soil. Okay, the last one’s not a fit, but it’s useful if you want to learn what it likes.

Northern blue flag grows along streambanks, shorelines, marshes and sedge meadows. A sedge meadow is a type of wetland populated by sedges and water-loving grasses.

Let’s dwell for a moment here, since it tells us about the niche this plant fills—not just the ecological one, but the horticultural one. Maybe you don’t live on a river. But do you have a wet, mucky place in your yard? This plant would like to go there. Clay soil? Put it there. Part of the yard that gets flooded? Put several of it there and let it start a rain garden. One university extension article suggests it does fine even under “4 inches of standing water.” Just make sure it gets a lot of sun.

Native range

Northern blue flag iris is native to the eastern U.S. and parts of southern Canada. Its range stretches south to the northern edge of Florida. It also grows in the north central part of North America, including Iowa, Minnesota, Michigan, and the southern edges of Manitoba and Ontario.

By comparison, southern blue flag’s range extends from Florida north to the mid-Atlantic. It extends further west, too; the northern species peters out before reaching much of the south central U.S.

Who it feeds and shelters

Pollinators

Mostly pollinated by bumble bees and long-horned bees. Hummingbirds, hummingbird moths, and butterflies are also sometimes attracted to the flowers.

The sepals (or falls, or just “the big showy parts”) work like landing pads that guide visitors to nectar. To do this, they have to brush past the anthers, getting coated with pollen in the process.

Host plant

In its native habitat, northern blue flag provides shelter for amphibians and insects. It hosts a handful of butterflies and moths, such as the Iris borer moth (Macronoctua onusta), Virginia ctenucha (Ctenucha virginica), and according to at least 1 iNaturalist observation, the smeared dagger (Acronicta oblinita).2

Weevils, flies, aphids, and other insects feed on this plant, but as usual, there’s a little less interest in things that aren’t Lepidoptera (butterflies and moths).

Poisonous for mammals

Iris versicolor’s roots and leaves contain a chemical called irisin or iridin, which is what several sources delicately refer to as a “purgative irritant.” Means that eating irises can cause uncontrollable pooping. Not great—unless you are a gardener hoping to plant something deer and rabbit won’t eat.3

How it spreads

Spreads through roots (rhizomatously) and seeds. A rhizome is technically an underground stem that can sprout new shoots and roots—and whole new plants. When it spreads this way it forms clumps, and eventually whole colonies. Its seeds often float away to a new location in water. Spreading seeds this way is called hydrochory.

You can divide northern blue flag

To divide a clump of northern blue flag, dig it up and pull the rhizomes apart, making sure each has at least a fan of foliage and some roots. Then replant them.

How people have used it

Various Native American peoples used this plant’s roots for a variety of reasons, including treating wounds and dressing burns.4 Two peoples, Mi’kmaq (or Micmac) and Penobscot, both indigenous to what is now the U.S. northeast and southern Canada, may have used it for treating cholera.

As a reminder: this plant’s roots are poisonous for mammals. Presumably people who used it knew how to prepare it. You shouldn’t if you don’t!

The Potawatomi people (Great Lakes region) used the leaves in basket weaving.

Iris versicolor is the official provincial flower of Québec.

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Northern vs. southern blue flag (Iris virginica)

The most reliable difference between northern blue flag and southern blue flag is that the northern’s flowers are taller than its leaves. On southern blue flag, the leaves extend above the flowers.

Supposedly their colors differ. For example, northern blue flag’s flowers are often described as deeper violet with more prominent veining, and southern blue flag’s signal is a brighter yellow. However, I’ve now spent quite a lot of time looking at both species. And these things tend to be true on average. Which I don’t find all that useful for confidently identifying a plant.

The northern species is cold hardier, the southern heat hardier. But also, they hybridize where their ranges overlap, making the whole idea of distinguishing them a bit of a fool’s errand.

And they start from a seed that’s about the same size as the sprinkles you top your ice cream with.

Seeds germinate all the time, in places you put them and places you didn’t. It’s therefore easy to overlook these little botanical starter kits. And honestly, while giant sequoias are magical, so’s the much more diminutive Pennsylvania Sedge, which blooms like a firework that’s afraid to make noise. A seed made that—or at least made it possible.

Let’s take back the “seed funding” metaphor from the business folks for a minute. You, the gardener, are an investor. You want your seed to become a seedling. And then eventually to have enough resources to start manufacturing cucumbers or flowers or whatever. But you’re not in there doing the day-to-day tasks of absorbing sunlight, converting it to chemical energy, taking up nutrients, and so on. You’ll just be having regular chats with senior leadership, making sure they have what they need.

And the first thing they need, long before they set down literal roots, is less (chemical) red tape.

The right conditions

Summer vegetable and herb seeds require very little work to get started because we’ve spent so much time breeding them that way. Biologists even have a name for this: easy, quick germination is part of a suite of characteristics associated with “domestication syndrome.” That is, people have selected for them so that they could more easily grow food.

The peppers, cucumbers, zinnias, cosmos, and melons you want to grow in the summer will germinate if you follow the instructions on their seed packs. To take this a step further, you could learn a little about where they’re from, and what conditions they’ve adapted to.

Peppers, for example, are probably from tropical parts of Peru, Ecuador, and Colombia. This is why pepper seed packs tell you they germinate best when the soil’s warmer (around 80°F, 26°C). Most people don’t have any 80°F soil lying around when it’s pepper-starting time. You can fake it though with a heating mat or a little greenhouse cover on your seed starting tray.

Seeds that haven’t been “domesticated” have dormancy mechanisms

If people haven’t spent thousands (and thousands) of years domesticating a plant, then its seeds probably still have dormancy mechanisms. These keep them “asleep” until the right moment, or as a biologist might put it, in “synchronization with the environment.”1

For example, species that are native to cold places, such as black-eyed Susans2, anise hyssop, and coreopsis, have a hard seed coat that prevents water from getting in and starting the seed’s engines at the wrong time. Imagine you are a seed from a cold place. You don’t want to germinate on a warm October day and then get hit by winter’s long, cold truck. To keep from doing this, you have a hard seed coat that “melts away” over months of cold and wet, i.e. winter.

In addition to the physical barrier, winter-dormant seeds have a chemical layer of protection. Winter reduces hormones that prevent growth (such as abscisic acid) and increasing ones that encourage it (such as gibberellic acid). This allows plants to germinate when it warms up in the spring.

Winter isn’t the only condition that’s dangerous for plants. Death Valley, California, gets about 2 inches of rain per year. (We got that here in New England last week.) So species like summer poppy (Kallstroemia grandiflora) and devil’s claw (Proboscidea parviflora) have a sort of “checklist” for when it’s ok to grow. They need an inch or so in autumn, and then another inch through March.

Other species, like wild lilacs (Ceoanthus species) use fire as an indicator. This clever mechanism allows them to grow when there’s not as much competition, and when they’re less likely to be shaded out. They can sit in the soil for more than 200 years waiting for the right time.

The native-seed-starting gardener needs to learn some new vocabulary

Breaking dormancy is probably one of the barriers for people interested in starting native plants from seed. In theory, you could hurl them into your garden and ask your preferred deity to take the wheel. But most gardeners want to feel more confident about planting.

Fortunately, native plant people have some tricks. For example, you can use the milk jug method for seeds that need cold and wet (stratification), a method invented by American gardener Trudi Davidoff in collaboration with the U.S. Department of Agriculture. Davidoff supposedly said, “If it’s not easy, you’re doing it wrong.”

Imbibition

Once dormancy “breaks” and conditions are right (warm enough, moist enough, etc.), the seed’s ready to grow. Next is imbibition. Imbibe means to drink, and that’s what the seed does—takes in water. Internal enzymes activate. Energy stored in chemical form releases.

The seed is not getting light or nutrients at this point. Just water and oxygen. Oddly, it may be “aware” that there’s light close by, since that’s a germination cue, but it doesn’t have any way to photosynthesize yet.

Finally, the seed root, or radicle, emerges.3 It takes in water and nutrients from the soil or whatever medium you’re growing it in. This is a delicate time. If the radicle rots, the seedling will die. This is called damping off and is a big reason that when you start seeds indoors, you should use a mix designed to have plenty of drainage.

The seed stem (hypocotyl) pushes up next. This is often the first thing the attentive gardener notices. Once the seed stem breaks the soil surface, it turns green. In many species, it’s bent over like a hook shape to protect the delicate tip. As it comes up, friction with the soil usually helps pull the seed cap away, though sometimes you’ll see it get stuck on top of the stem. You can gently brush it away if it doesn’t fall off on its own.

As an aside: This is a reason it’s important not to plant your seeds too deep. It takes precious energy to push up to the surface. A paper published by the USDA’s research division dryly reports that deeply-planted seeds might germinate, but “seed reserves may be exhausted before the seedling reaches the soil surface, which leads to seedling death.”

Finally, plants unfurl their cotyledons, or seed leaves.

Cotyledons are packed with nutrients from when the seed was formed. Seedlings can break these nutrients down and use them. Some species have two (dicots), and others have just one (monocots). Some keep them underground, where they provide nutrients, and others above ground, where they start photosynthesizing.

Most seeds’ supplies will be running a little low after accomplishing all this. They’ll have to begin gathering what they need from their environment.

How does the seedling know which direction is “down”?

Plants have a very cool way of knowing which direction to grow. Plant cells have little components called statoliths. These are heavy and settle on the bottom of the cell. Plants are able to use the location of these statoliths to “figure out” which way is down. Essentially, they can sense gravity.

This is why no matter which direction you plant a seed in, the radicle will grow down, even if it has to curve.

Plants can also sense light and move toward it. But this phototropism is separate from the gravitropism that helps the root grow in the right direction.

Indiana University has a very cool video of corn seed radicles emerging and growing in the right direction, even though seeds are oriented in different directions.

Ranunculaceae is a family of at least 3,700 species. Here are some you might know:

• Ranunculus (Ranunculus spp.)

• Columbine (Aquilegia spp.)

• Hellebores (Helleborus spp.)

• Anemones (Anemone spp.)

• Clematis (Clematis spp.)

• Marsh marigold (Caltha palustris)

• Larkspurs and delphiniums (Delphinium spp.)

• Hepatica (Hepatica spp.)

• Lesser celandine (Ficaria verna), though not greater celandine, which is in the poppy family

Common characteristics

Flowers have many stamens and (usually) many carpels

The most reliable characteristic of this family is one you need to look closely to see: lots of stamens and carpels.

Ranunculaceae species often have dozens and dozens of stamens. Many species also have lots of carpels, though not always.

Flowers: with lots of exceptions, appear to have five petals and are symmetrical in more than one way

Ask this family how many petals it has, and like a teenager describing what it did in school that day, it’ll say, “Oh, five.” In fact, it often has more than five, and some of its petals are actually sepals. But it doesn’t want to get into the details with you.

Flowers in the Ranunculus genus do usually have five petals. And a few other genera, like Anemone, appear to have five petals, but actually have sepals that look like petals. Sepals are leaf-like structures that protect flowers. Botanists distinguish them based on the type of tissue they’re from, which doesn’t help us much as identifiers without microscopes.

Another sometimes-works identifier is that many flowers in this family are radially symmetric, or symmetrical in more than one way. There’s even another trivia word for this, actinomorphic.

Unfortunately, there are exceptions. For example, plants in the monkshood and delphinium genera can only be divided in half one way. The terms for this are bilaterally symmetrical or zygomorphic.

Lobed, alternate leaves

Most plants in this family have leaves with deep grooves in them. They also usually alternate on their way along a stem (they don’t grow across from each other).

Of course there are exceptions. Lesser celandine (Ficaria verna), a destructive invasive here in the U.S., has leaves with gently waving edges and a notch at the base.

Foragers beware: Most buttercup family plants are toxic

Ranunculaceae contain chemicals that can cause blisters and rashes. A very cool bit of plant engineering makes this possible.

They can’t store the blister- and rash-causing substance, called protoanemonin, directly. That would harm their own tissues. Instead, they store it in a chemical form called ranunculin, a little plant biohazard container. When something chews on the plant, it releases enzymes that open the container, which “sprays”—to use some artistic license—the protoanemonin all over the unsuspecting herbivore.

For this reason, it is better to be a suspecting herbivore. Don’t eat plants in this family, and tell your pets not to, either.

Wildlife value

As pollinator plants

Many Ranunculaceae bloom in spring, which is important for early-emerging pollinators. Where I live in the U.S. northeast, these include bumble bee queens, mining bees (Andrena species), a few species of cellophane bees (Colletes spp.), and some hoverflies.

For example, red columbine (Aquilegia canadensis) is an early-bloomer known for attracting hummingbirds. A couple of species of globeflowers in Europe and China have been studied because of their specialized fly pollinators. And in the U.K., stinking hellebore (Helleborus foetidus) is an important food source for bumble bees in February. (Incidentally, I recently wrote about a phenomenon where yeasts heat up the nectar in early-blooming hellebores, creating little saunas for bumble bees.)

Many species in this family are not just early bloomers but spring ephemerals, plants that flower and set fruit before trees put out their leaves. They bloom especially early, when very few other plants have emerged. Though they provide critical food for early-emerging insects, they also have to jump through a few hoops to make sure they attract those insects.

For example, one interesting study proposes that star-shaped winter aconite (Eranthis stellata) has evolved “elaborate petals” with “multiple functions, including color contrast, [guides for finding the nectar], a nectar reward for bees, and food deception and a pollen reward for flies.” This is a lot more work than your typical fall-blooming aster has to do, for example.

One paper found that five early-season Ranunculaceae species produced pollen but almost no nectar. This is interesting in that it speaks to early-season bees especially needing the protein- and fat-containing pollen for rearing their offspring.

For shelter and food

Most mammals don’t want to eat Ranunculaceae plants, given the whole blistering-the-inside-of-your-mouth thing. That said, they may be willing to take a chomp if they’re desperate or if the plants are young and unestablished. And evolution’s creative. A few insects actually do tolerate the chemical weaponry.

A leaf mining fly, Phytomyza ranunculi, lays its eggs on plants in this family. Leaf mining is a way of feeding where insects eat the inner tissue of leaves.

Two generalist caterpillars include Ranunculaceae plants in their diet, too: the Hebrew character (Orthosia gothica) and the small angle shades (Euplexia lucipara).

Interestingly—if you are a nerd—a few other moths are thought to eat Ranunculaceae, but perhaps incorrectly. For example, a few sources list monkshood (Aconitum spp.) as a food source. But in a 2021 paper, a researcher observed “high mortality rates among larvae” that were fed monkshood compared to ones fed dandelions.

Value for people

We eat almost nothing from this family with one notable exception. We use the seeds of Nigella sativa as a spice (black cumin or black seed), particularly in Indian, Middle Eastern, and North African cooking.

We do like looking at them, though. Popular garden plants include hellebores, larkspur, delphinium, and various species of clematis. Marsh marigold (Caltha palustris) is beloved among native plant nerds where I live, though perhaps not as much as red columbine.

Several plants are medicinally important within their cultural contexts, too. These include the previously mentioned black cumin, black cohosh (Actaea racemosa), and goldthread (Coptis spp.).

The ranunculus from the flower shop

You might include ranunculi in arrangements you bring home from the florist. The Ranunculus genus, by the way, includes some 1,600 species and has been bothering taxonomists for centuries. (A 2010 paper recommended splitting it into multiple genera.)

But the ones we get from the florist are, in some ways, less interesting than those we don’t. Like roses, these have been bred to look more attractive to people and to be less useful to wildlife. For example, cultivated ranunculi tend to have double flowers, which means a lot more petals and less pollen, nectar, and accessibility for pollinators.

Main sources

Family characteristics

• A molecular phylogeny, morphology and classification of genera of

  Ranunculeae (Ranunculaceae) | Taxon, accessed through Wayback Machine

• Ranunculaceae | Wikipedia

• Ranunculaceae Juss. | World Flora Online

• Ranunculaceae in Flora of North America | efloras.org

• Plant Taxonomy 10a3, Ranunculaceae | Nic Tippery, YouTube

• RANUNCULACEAE | Botanical Dermatology Database (Has a huge species list, though not a particularly accessible website)

Ecology

• Feeding the bees in winter | Bumble bee Conservation Trust

• Life history of the rare boreal tiger moth Arctia menetriesii (Eversmann, 1846) (Lepidoptera, Erebidae, Arctiinae) in the Russian Far East

• Phytomyza ranunculi | NatureSpot

• Picking Plants for Pollinators: The Cultivar Conundrum | Xerces Society

• Pollen food resources to help pollinators. A study of five Ranunculaceae species in urban forest | Urban Forestry & Urban Greening, 2021

• Pollination Strategies of Eranthis stellata (Ranunculaceae), a Spring Ephemeral with Elaborate Petals | Biology, accessed through PMC

• Nectar yeasts warm the flowers of a winter-blooming plant | Proc Biol Sci, accessed through PMC

This post is a summary of a study, “Nectar yeasts warm the flowers of a winter-blooming plant,” published by Carlos Herrera and María Pozo in 2010 in Proceedings of the Royal Society B: Biological Sciences, available open access through PubMed. Because it makes for a more complete and interesting story, it also covers some of the authors’ follow-up research.

What they studied and why

There are yeasts out there in the world. A yeast is a lifestyle choice, where a fungus lives as a single-celled organism that reproduces through budding or fission. Later, maybe it’ll transition to being a strand of cells that graffitis old bread with colorful fuzz.

Anyway, it’s probably freeing to live as a yeast, because you can do it all over the world, from deep-sea vents to arctic soils to the nectar in flowers.

Nectar’s a nice place to be if you’re living as a yeast. It’s got lots of sugar that you can metabolize, a process where you absorb energy from sugar molecules. When you do this, you create a little burst of heat.

In a 2010 study, researchers Carlos Herrera and María Pozo wanted to learn if yeast metabolism makes enough heat to actually warm up nectar, as well as the air around the nectar. The specific fungus in this study is Metschnikowia reukaufii, which spends most of its life as a yeast and specializes in flower nectar.

Why is this interesting? A 2008 study that Herrera co-authored found that yeasts actually hitch rides to flowers on bumble bees.

The two bumble bees in that study, early bumble bee (Bombus pratorum) and buff-tailed bumble bee (Bombus terrestris), were on their way to and from a plant called stinking hellebore (Helleborus foetidus). These bumble bees are known as important early pollinators of stinking hellebore—or you could flip the relationship and say that stinking hellebore is known as a critical early-season food source for bumble bees.

So, bumble bees bring yeasts to flowers, and yeasts eat the sugar in nectar and release heat. If that heat is enough to warm the nectar, then perhaps it’s a little like offering the bumble bee a warm bath on a cold day. Bees might be more likely to visit a flower if they get a free spa session along with their meal, which would improve the flower’s reproductive odds. This is rose-colored glasses ecology: a little love triangle involving three separate kingdoms where everybody’s getting what they need.

On the other hand, making heat requires the yeast to eat the sugar. Eat enough sugar and there won’t be much left in the nectar. Bees would then visit less, flowers would have less sex. This is a more ominous picture; the yeast is acting as a parasite on the relationship between flowers and bees.

Two sites, two locations, two experiments

Researchers located two clusters of stinking hellebores at two different locations. They tested flowers in pairs, 7 pairs at site one, 10 pairs at site two. One of each pair was left alone (the control), and the other was modified (experiment or treatment).

Experiment One prevented flowers from developing yeast. Experiment Two added extra yeast. They also bagged experiment flowers so pollinators couldn’t get to them. This prevented bees from bringing yeast to treatment flowers in Experiment One, and from modifying yeast amounts for treatment flowers in Experiment Two.

Then, on whatever day was designated Official Experiment Day, they measured the temperatures of the nectar and the air just above the nectar.

They ran Experiment One at both sites and Experiment Two only at one. They don’t say why; I assume it was for a typical something-logistical-went-wrong reason.

Both locations, by the way, were in the mountains in Spain, in the understory of a black pine forest. Bumble bees visited regularly throughout the experiment, though they couldn’t access the bagged flowers.

About stinking hellebore

Helleborus foetidus is a buttercup family species (Ranunculaceae) that blooms in very early spring, February to April, depending on the location. It’s native across western Europe and in the U.K.

Stinking hellebore creates clusters of flowers, sometimes as many as 75 per cluster. Each flower contains 5 nectaries, and each of those contains up to 5 microliters of nectar. A microliter is a millionth of a liter. If it helps you visualize: there are about 4,930 microliters in a teaspoon. And an aside, it boggles the mind that we can know how much nectar is in a flower’s nectary.

This nectar being available early in the year is what’s key. For example, a Royal Horticultural Society article observes that stinking hellebore is a “wonderful native plant that flowers in even the coldest weather and is adored by bees.”

That yeasts might warm these flowers in cold weather, further benefiting bees, is a lovely idea—the kind of neat summary that makes us think nature’s got everything figured out. But let’s not get ahead of ourselves. Is yeast actually warming flowers? And if it does, is that actually good?

What they found

All the unbagged (control) flowers had yeasts, which is what one would expect with regular bumble bee visitors. Interestingly, the interiors of all flowers, even unyeasted ones, were warmer than the air around them. Herrera and Pozo suggest that this is because of the stamens and carpels, or reproductive parts, breathing. (All parts of plants “breathe,” or release carbon dioxide and some heat, but I’d speculate that the stamens and carpels do so more than other plant parts, which is why they’re being highlighted here.)

But the yeasty flowers were warmest. Here’s a summary of how much warmer the nectar and flower air were compared to the ambient air.

• Experiment 1, Treatment (yeasts removed): Nectar 1.6°C warmer, flower air 0.8°C warmer

• Experiment 1, Control (left alone): Nectar 3.1°C, flower air 1.2°C

• Experiment 2, Treatment (yeasts added): Nectar 1.9°C, flower air 0.7°C

• Experiment 2, Control (left alone): Nectar 1°C, flower air 0.5°C

A few notes on these results:

1. To convert temperatures to Fahrenheit, multiply by 1.8. So 3.1°C is about 5.6°F.

2. Flower air specifically refers to the air inside the flower, immediately near to the nectar. The authors refer to it as the microenvironment inside the flower.

3. You might be wondering, why did the control in experiment 1 get so warm? The paper doesn’t explicitly address this, but a couple things are relevant. First, they only did experiment 2 at one of their 2 study sites, so there’s different data underneath those numbers. Second, they did experiment 1 in March and experiment 2 in April. The weather was different, the bee visits were different, etc.

4. You want this to be a table. I also want this to be a table. As far as I know, there’s no way to create an accessible table on Substack. So we’re stuck with bullets.

The authors do some weedsy number crunching with their results that you should review if you’re interested. For our purposes, their key takeaways are that more yeast results in higher temperatures. Every tenfold increase in yeast means about .66°C (1.2°F) warmer nectar. Individual flowers with very high yeast densities had nectar that was 5-6°C (9-11°F) warmer than the outside air. That’s much, much warmer. Imagine if someone you lived with turned your thermostat up that much. You would notice.

The high temperatures weren’t outliers, either. The researchers report that about 20% of nectaries in exposed flowers were at least 4°C warmer than the surrounding air.

What it means (the “so what?”)

As a reminder, the scope of this paper is narrow. The researchers just wanted to know if yeasts make nectar and flower air temperature warmer. That’s it. Their results don’t tell us about bumble bees treating nectar as a warm cup of tea on a cold day, or yeasts parasitizing the bee/hellebore relationship. A difficult thing about science is that it takes tiny steps, each of which generally needs some argument. Such is the nature of making knowledge.

That said, the researchers are absolutely interested in all of those things. So the “so what?” includes both “what this tells us” and “what this implies could be true (and should be studied).”

Ecological throuples

This study is about three species from three different kingdoms in a relationship with each other. Bumble bees go to flowers for nectar. Yeasts hitch a ride on bumblebees, also for nectar. Once yeasts are in nectar, the heat they put off might attract more bumblebees.

Even if there was nothing else to learn, that’s an eye-opener. Next time you see a bumble bee on a flower, know that you might be—probably are—seeing a three-way interaction.

A third way that flowers might warm themselves

This is the third way we’ve discovered that flowers might warm their immediate environment. They also do this in two other very cool things:

1. Absorb sunlight (through their shape, color, or physically moving with the sun)

2. A science fiction-sounding ability called thermogenesis, where flowers essentially make their mitochondria breathe real fast to generate heat. Eastern skunk cabbage uses this to physically melt snow when it comes up in early spring.

These techniques aren’t available to all flowers. Helleborus foetidus, for example, lives in the understory, where there’s not that much light to absorb. The researchers say that “this suggests the intriguing possibility that in cool, shady forest environments,” yeast could substitute for direct sunlight. “Intriguing possibility” in a research paper is the equivalent of a regular person grasping you by the shoulders, pointing at something, and screaming, “Isn’t that so cool?!”

The reason they think it’s so cool is that it suggests a variety of “ecological consequences.” (Heavy emphasis on suggests, which will become very important in the next section.) For example, other studies have shown that warmer flowers help plants reproduce for a variety of reasons, including:

• Increasing pollinator visits. A warm flower is a nice treat for a bee on a cold day.

• Bluntly, makes plant sex work better. Pollen grains have an easier time doing all the things they need to do once they land on a stigma—germinating, growing a tube, fertilizing an egg

• Helps fruit develop

• Makes bigger seeds

In other words, if you’re a flower, finding a way to raise the temperature makes it more likely that you’ll reproduce successfully. A person looking to find a mate might dress nicely, work out, go to therapy, get a good job and a stable life. A flower might host nectarivorous yeasts. We’re not so different, right?

They do note a major potential tradeoff, though. Yeast warm means yeast physically eating the sugar in your nectar. Bumble bees might not like a warmer flower if it doesn’t have much sugar left. They might choose a cooler but sweeter site instead.

Follow-up research: “Howevers” and “Well, actually’s”

This paper proved that yeasts do make flowers warmer. And so, as you might imagine, Herrera and Pozo next wanted to learn if yeasts actually did contribute to better flower production. That’s what they focused on in their 2013 follow-up study.

In a jarring second-act turn, they reported that yeasty flowers did attract more bumble bees, but at the cost of reproduction. This was because yeasts ate so much of the nectar that they actually harmed flower reproductive activities. That is, they were sort of like a reverse aphrodisiac. Not good wingmen.

But other research complicates the picture further. Vannette, Gauthier, and Fukami (2013) found that bacteria, and not yeast, negatively affected flower fertility. This line of research really messes with my “throuple” and “love triangle” framing, since it points out that this is a complex system with lots of moving parts and actors.

And then in 2017, Herrera, this time with another researcher named Mónica Medrano, studied if the heat effects alone were beneficial. That is, they separated the Yeast Eating All The Sugar variable from the Nice Warm Flower variable. They found early-blooming plants benefitted reproductively, but late-blooming plants suffered. One reason for this might be that bumble bees like a warmer flower when it’s cold out, but they don’t when it’s warm out.

Where this leaves us

The story of this ecological love triangle turns out to be a messy, complex relationship between more species than we commonly think. Intuitively, the presence of yeasts in hellebore nectar should be a net positive for everybody involved in this story. If it wasn’t, evolution would’ve put a stop to it one way or another.

But the results of these studies don’t let us say, “What a nice, mutually beneficial relationship! Representatives from three of the kingdoms collaborating and cooperating.” Instead, we have an image that’s as fuzzy as a buff-tailed bumble bee’s butt: a relationship that’s sometimes beneficial, sometimes harmful, and where none of the actors is fully in control.

Northern spicebush is a fairly large shrub, up to 12 feet tall and 12 feet wide. It’s shorter and bushier if it gets a lot of sun.

It’s one of the first bloomers each spring and has striking little yellow flower clusters. When crushed, they smell a little like crushed allspice and lemon zest.

The bright yellow spring flowers are also why this plant sometimes appears on replace-these-plants-with-native-alternatives lists as a forsythia substitute. Bluntly, forsythia in spring is stunning, almost sickeningly so. It has the mass appeal of grocery store buttercream. Spicebush is more a smattering of bright yellow. Think fancy-bakery-oatmeal-raisin-cookie situation. We can still make a popular appeal for spicebush over forsythia, but not on blooms alone.

The leaves also smell like a kitchen that’s been baked in, spicy and citrusy. They turn yellow in fall. Leaves alternate along branches (they’re not directly opposite one another). They’re simple, widest in or just past the middle, with smooth edges. If you ask a child to draw a leaf, you might very well get something that looks like a spicebush leaf.

Flora of North America calls the leaves obovate, which means they’re narrowest at the base. Imagine an egg with the pointy end attached to the stem. That’s obovate.

However, the leaves often have pointy tips, which just makes them look like both ends are equally narrow.

Spicebush bark has very noticeable white, oval-shaped lenticels. Lenticels are pores that let bark breathe.

Plants with female flowers (that get pollinated) make little red fruits. Botanically, these are drupes, or fleshy fruits containing exactly one seed. They’re slightly oblong. These are typical laurel family (Lauraceae) fruits.

Where it lives

Habitat

Lindera benzoin likes the wet, rich soil of deciduous forests (made up of trees that drop their leaves for the winter). Apparently, early land surveyors used it as an indicator of good farmland.

As an understory shrub (that is, living under the canopy of trees), it can handle shade. One study found it may gather a lot of its light energy in the early spring, before the trees leaf out. That said, it does well in sun, too, dedicating more energy to leaves and less to height and branching.

It likes to be near streams, swamps, and various waterways, more so than most understory shrubs. If spicebush were a person, it would want to sit in a folding chair in the shade by a creek. Maybe work on its paintings or fish.

A lot of sources mentioned that it often grows near tulip tree (Liriodendron tulipfera). They don’t depend on one another or anything; they just like the same conditions. This is a useful indicator for gardeners, since if you have one you could also potentially plant the other.

Native range

Spicebush is native across most of the eastern half of the U.S. Its range extends up into Canada (southern Ontario) and down through Texas.

Who it feeds and shelters

Pollinators

Lindera benzoin is an early bloomer with small, easy-to-access flowers that are enjoyed by early emerging bees and flies. These include:

• Mining bees (Andrena genus)

• Sweat bees (Halictidae family)

• Plasterer or cellophane bees (Colletes genus)

• Hover or flower flies (Syrphidae family)

• Bee flies (Bombyliidae family)

If you’re not an insects person, this list may just be a name dump. So here are a couple tidbits.

• A single margined calligrapher fly larva (Toxomerus marginatus) eats literally hundreds of aphids before it pupates (that is, turns into an adult).

• Andrena erigeniae, the spring beauty mining bee, nectars on spicebush, but will only eat pollen from spring beauty (Claytonia virginica). When she does this, she gets coated in pink fluffy pollen and appears to be wearing pink pants.

As a host plant

Among plant nerds, this species is probably most famous for being chomped on by swallowtail butterflies (Papilio genus). The adult spicebush swallowtail (Papilio troilus) is traffic-stoppingly stunning—and so is the caterpillar, in its own way. The latter has these large fake “eyes” that are intended to make it look like a little snake, warding off birds and other predators.

Lindera benzoin also hosts the eastern tiger swallowtail (Papilio glaucus, also a looker) and in the southeast of its range, the Palamedes or Laurel swallowtail (Papilio palamedes, also striking).

Because the butterflies are so impressive, you hear less about another lepidoptera that develops on this plant: the promethea silkmoth (Callosamia promethea). Their cocoons hang on the plant all winter.

The HOSTS database lists 16 butterflies and moths that use northern spicebush as a host plant. It may also host other insects, such as the sassafras borer beetle, but other insects don’t get as much attention as butterflies and moths.

Finally, like other understory shrubs, this one provides critical shelter for birds and small mammals.

Birds and mammals like the fruit and leaves

Spicebush fruit contains a lot of fat, which makes it a great energy source for birds, especially migratory ones. Wood thrushes are often cited as associated with spicebush, perhaps because they use it for shelter in addition to food. A recent 3-year study observed 24 species of birds feeding on spicebush. Each season, the most common visitor was Swainson’s thrush. Brown thrashers, American robin, and northern cardinals were also frequent visitors.

Mammals will also eat the berries, including eastern cottontail rabbits, raccoons, and opossums. There’s some debate about if deer will browse the leaves; I imagine it comes down to how desperate (and overpopulated) the deer are.

How it spreads

Spreads through cloning itself through its roots and by seed.

Spicebush can send out roots laterally. These produce adventitious buds—which basically means “a bud in a weird place”—that send up new stems. Each new stem becomes a new spicebush. Over time, you get big colonies of the shrub. Members of the colonies are clones of the parents that spawned them.

To editorialize for a moment: this is a weird strategy for a plant that keeps male and female flowers on separate plants (dioecious). Each clone is the same sex as its parent, so you can get big colonies of only males or only females. It has to make spicy plant love to make seeds.

This is relevant if you want to grow spicebush. You’ll only get fruit if you have a male and a female plant, and you can’t tell until they flower (three or more years in). So you likely need to plant a few and hope you get both sexes.

When it does produce seeds, it spreads in the usual way: bird eats berry, poops out seed, seed sprouts, etc. This other way of spreading helps spicebush colonize new sites. It also provides genetic diversity, since cloning involves making an exact copy of the parent.

Spicebush seeds die if they dry out. The botanical word for this is recalcitrant. This means if you purchase spicebush seeds, you need to keep them in moist sand (or something similar) to keep them viable. In nature, they rely on the moisture in the soil of their preferred environments.

How people have used it

As its name suggests, spicebush has a history of being used in cooking. During the revolutionary war, colonists used the fruits as a substitute for allspice. They may also have learned from the Cherokee that it could be used for tea, along with flavoring various dishes.

Native peoples used this plant for medicinal reasons as varied as treating colds, measles, and to induce sweating (that is, as a diaphoretic).

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Sources this is from

• HOSTS - a Database of the World’s Lepidopteran Hostplants

• Lindera benzoin | Flora of North America

• Lindera benzoin | Flora of the Southeastern US

• A model of patch dynamics, seed dispersal, and sex ratio in the dioecious shrub Lindera benzoin | Journal of Ecology

• Northern Spicebush (Lindera benzoin) | bplant.org

• Northern Spicebush, A Great Shrub for Birds (and More) | North Carolina Native Plant Society

• Search for spicebush | BRIT, Native American Ethnobotany Database

• Spice Up Your Garden with Spicebush | Penn State

• Spicebush | Outdoor Learning Lab

• Spicebush | USDA

• Spicebush | Holden Arboreum (has a cool diagram of the leaves and fruit)

• Phenoseasonal subcanopy light dynamics and the effects on Lindera benzoin | PMC

• Use of northern spicebush (Lindera benzoin) berries by birds and mammals in Southern Appalachia | T&F

Rules like these are meant to help us wait until it’s warm enough for tomatoes to do well outside. But what about in years like this one, where it’s past the threshold, but still 40°F at night? Can I risk putting them out a little early? The Tomato Shuffle, where you run them outside during the day and then back to the grow lights at night, gets tedious pretty quickly.

A 2024 paper, “Recent Insights into the Physio-Biochemical and Molecular Mechanisms of Low Temperature Stress in Tomato” (Kwanuk Lee and Hunseung Kang in the journal Plants) reviews the main things we know about how cold affects tomatoes. In this piece, I’m going to summarize in plain language the parts of the paper that are relevant to home gardeners. This helps us understand when to plant tomatoes outside with a little more nuance than a calendar milestone does.

But first: what counts as “low temperature”?

Unfortunately, the one thing this paper doesn’t do is define low temperature. I’ve heard that 50°F (10°C) is too cold. Other sources suggest 65°F (18°C) or more. Depending on where you live, this could mean waiting quite a while, since soil temperatures rise more slowly than air temperatures, and cold roots are at least as bad as cold leaves for tomato plants.

A 1993 study described germinating plants at 77°F (25°C) and then studied what happens to different plants if you reduce the temperature to 64°, 59°, and 54°F (18°, 15°, and 12°C). They found that the 64° group grew significantly better than the 54° group. However, plants in the 54° group didn’t stop growing; they just grew more slowly. So the takeaway here is that tomato growth slows near 50°F and accelerates as you move toward its ideal temperature of around 80°F (27°C).

The home gardener in a not-warm place needs to be practical; cold does set tomatoes back, but you probably don’t want to wait until June to start hardening your plants, let alone transplanting.

I’m going to continue using 50°F (10°C) as the threshold for when plants begin to feel the effects of cold damage. But if you live in a warm place, you can choose a higher threshold. Anyway, here are some things the Lee and Kang paper describe going wrong for tomatoes when it’s cold.

Tomatoes germinate and grow poorly in cold

Cold can delay and even prevent tomato seeds from germinating. Tomato plant cells also divide more slowly in the cold, i.e. they grow more slowly. This is one reason we typically start them inside: it lets them get going faster and avoid unseasonably warm spring days that might trick them into germinating early.

Cold causes tomato plants to produce smaller, thicker leaves they would if it were warm. This is good for survival, but bad for things like photosynthesis. Mature plants produce fewer flowers (and thus fruits) in cold weather.

Less chlorophyll (the molecule that allows plants to absorb light)

Cold-stressed plants make less chlorophyll while they are cold. Chlorophyll is a molecule that absorbs mostly blue and red light so that plants can convert it to energy. As an aside, this is one reason plants appear green. They’re absorbing red and blue light and reflecting green light. Kind of ironic; we see the light they’re rejecting, not the light they need. Anyway, less chlorophyll means less light absorbed. Less light absorbed means less energy to use on what you want to slice up and put in a sandwich.

Cold damages plant cells, which causes them to lose water and nutrients

Plant scientists use an indicator called electrolyte leakage to identify when a plant’s cells are damaged. A paper that describes how to measure electrolyte leakage explains it this way:

When a cell dies and loses the integrity of the cell membrane, electrolytes, such as K+ ions, leak out of the cell. Thus, we can use the amount of electrolytes leaked from a tissue as a proxy for the extent of cell death in the tissue.

In other words, when tomato plants get cold, cell membranes can’t do their jobs. They leak electrolytes and water. Seems bad.

Antioxidant defenses don’t work as well

Molecules that are reactive can cause a lot of trouble in bodies. You’ve likely heard the terms “free radicals” and “antioxidants” in the context of human nutrition. Plants also have these.

Free radicals are molecules with an unpaired electron. They badly “want” to pair this electron and will “take” one from another molecule. Antioxidants provide these extra electrons, which prevent free radicals from taking them from things whose stability you don’t really want messed with, such as DNA molecules.

Scientists can measure the concentration of oxygen-containing free radicals, along with reactive molecules that contain oxygen. They call these reactive oxygen species, or ROS. A small number of ROS is useful, helping plants respond to various types of stress. But lots of ROS are bad. You don’t want lots of desperate molecules zipping around your tomatoes’ bodies, stealing electrons. Chaos ensues.

Plants make enzymes that “scavenge” for reactive oxygen species. This helps keep ROS numbers manageable. However, in low temperatures, these enzymes are less active. This leads to higher, more toxic numbers of reactive molecules in the plant. It’s not technically correct to say that cold might “give tomatoes cancer,” but if that helps you remember this dynamic, I say go for it.

Fruits taste worse

You already know about this if you’ve purchased a tomato at the grocery store. Tomatoes are often stored cold to make them last longer. However, doing this makes them taste worse. This happens because when chilled, tomatoes lose volatiles, the chemical compounds responsible for flavor.

I can think of a few scenarios where cold fruit is relevant for home gardeners.

• If you know it’s going to get cold when tomatoes are ripening, you may want to cover your plants to protect them (row covers, blanket, etc.)

• If you pick tomatoes early to let them ripen indoors, don’t refrigerate them. You’d basically be simulating a cold night.

• I always have a few tomatoes hanging on the vine when it starts to get cold in the fall. In the future, I’ll pick any of these with any blush and let them finish indoors.

Conclusions

This isn’t everything that can go wrong for tomatoes in the cold. For example, a study that focused on cold soil temperatures also showed that plants with cold roots don’t photosynthesize as well. However, it’s enough for home gardeners to know that cold will set your tomatoes back significantly.

The major takeaway from this is, we need sustained, warmer air temperatures in spring to bring soil temperatures up. This year, for example, with temperatures still dropping into the low 40s, I’m still not quite ready to plant tomatoes outside, even if Mother’s Day’s already come and gone.

You can check soil temperature with a soil or compost thermometer. They cost less than $10 in a variety of places; just make sure it’s long enough to get down into the root zone.

A related takeaway is that many tricks people use to plant earlier protect from cold air, but not cold soil. For example, row covers warm the air beneath them but have less of an effect on the root zone. Straw and wood chip mulches might actually prevent soil from warming up in the spring, since they block sunlight. And I once saw someone set dozens of tealights on their raised bed, which looked pretty, but probably didn’t do much for the roots.

Finally, the paper I summarized is about tomatoes, but it’s safe to assume that other “warm-season” crops, like peppers and cucumbers, have similar biological challenges. As much as those of us who live in cooler places want to start our gardens’ engines this time of year, it’s best to wait until our weather is a good fit for our plants.

Sources

• Recent Insights into the Physio-Biochemical and Molecular Mechanisms of Low Temperature Stress in Tomato | MDPI (This is the paper I was summarizing)

• Effect of low root-zone temperature on photosynthesis, root structure and mineral element absorption of tomato seedlings | ScienceDirect

• Let soil temperature guide you when planting vegetables | Oregon State University

• Development of the Fifth Leaf is Indicative for Whole Plant Performance at Low Temperature in Tomato | ScienceDirect

• Quantification of Plant Cell Death by Electrolyte Leakage Assay | PMC

• Tomato Fruit Volatiles | van der Knaap Lab

• Reactive oxygen species generation and signaling in plants | PMC

But—and I acknowledge it’s kind of an annoying “but”—this is only part of the story of what bees, as a group, love. Garden variety observing (as well as professional observing, it turns out!) is shaped by a kind of informal detection bias. That is, when things are easy to observe, we’re more likely to observe them—and then those observations are more likely to structure the story we tell.

I want to poke at the typical story of what bees love, not to be provocative or irksome, but because I think there’s a better one. Among other things, it gives us an excuse to buy more plants.

The visibility bias

The most obvious explanation for bees loving something is not the flower, it’s the type of bee. Some bees just make it easy to see what they’re doing.

For example, honeybees tend to forage as a colony, and those colonies are notably huge. A honeybee scout can “tell” its hivemates about a patch of flowers, which results in lots of bees showing up. Quite noticeable from a human perspective!

Bumblebee colonies are much smaller, but they are still colonies, sometimes made up of hundreds of bees. And bumblebees tend to be quite large and conspicuous and bumbley. Four or five bumbles feels like a lot of bee.

By comparison, imagine you are an unequal cellophane bee (Colletes inaequalis). You’re solitary (though you do build neighborhoods of nests, or aggregations). You emerge in early spring, you head for the few restaurants that are open, such as maples, willows, serviceberries. These tend to be kind of far off the ground, but you don’t mind. You can fly, after all. You are not so likely to be observed by a gardener up there, but that’s not really something you think about.

If you’re male, you die after just a few weeks. If female, you maybe get a month and a half. Your larvae are tucked underground, sealed off and protected until they’re ready to emerge. The gardens in your neighborhood are still waking up, the gardeners inside and staring impatiently out their windows.

About 90% of our native North American bee species are solitary. That means Colletes inaequalis is one of about 3,600 species that are easy to leave out of a story about what bees love.

The horticulture bias

Imagine you are a spring beauty mining bee (Andrena erigeniae). Like about 25% of bee species in eastern North America, you specialize on a particular plant. You only forage pollen on spring beauty (Claytonia virginica or C. caroliniana), and when you do, you end up with pink pants.

You don’t really visit many gardens. You’ll take nectar from most flowers, but your larvae need pollen specifically from spring beauty. Most people don’t plant these. You Spoke With The Manager at the local plant nursery about this, but she shook her head. “Spring beauty is a short bloomer and it’s hard to maintain in pots. Plus, people just think tulips are prettier.”

So you’re not in gardens. You’re in an eastern deciduous forest on a flower smaller than a dime. People tend not to see you on plants in their yard, and thus rarely mean you when they say that bees love something.

The on-the-menu bias

Imagine you are a honeybee. You have five eyes. You’re looking for food, and you fly over a suburban lawn. There’s grass, dandelions, and clover. Clover’s pretty good. You like clover. You evolved to eat its pollen. You’re both from the same regions of Europe and Asia.

Dandelions are okay. You don’t actually love dandelions. Not enough nectar, pollen not filling. But it’s better than grass, which is notoriously short on nectar and pollen.

All things considered, you’re notoriously not a picky pollinator, but this restaurant’s kind of mediocre. There are plenty of flowers in North America you like, but they’re not common here in the suburbs. What there mostly is is grass. So much grass.

You and your hivemates get to work on the clover. From a few feet above, someone snaps a picture. “You guys really love this clover,” they say.

The I-can’t-see-the-future bias

One last bias, which is better illustrated with butterflies than bees, though the same principle applies.

Imagine you are a gardener, and you have a butterfly bush (Buddleia davidii). It’s covered with butterflies. It has large, obscene clusters of flowers with nectar that’s easy to get to. The butterflies love it!

You have an annoying neighbor, a Well Actually type. Well Actually says butterfly bush doesn’t host any butterflies. He says they only lay eggs on plants their larvae can eat.

Well Actually also whines about how butterfly bush can escape the garden and form colonies along riversides and displace critical native plants. Well Actually says butterfly bush is actually illegal to sell in many states now. It’d be better to put in something like buttonbush or viburnum or summersweet.

You’re sad to learn when you look it up that most of this is true. But it makes no sense! Look how many butterflies are on this plant! You can see with your own eyes that they must like it!

Things bees love that are harder to see

So what should the aspiring-to-support-wildlife gardener do besides look?

First, continue to be delighted when things are covered with bees. Bees are cool garden companions. But here are a few other chapters to add to the story.

Plants that bloom for a long time and have small flowers

Plants that bloom for a long time and have lots of small flowers are generally bee friendly. Mountain mint is a good example. Most mountain mints have hundreds of flowers packed into little clusters. They produce them continuously for weeks. The nectar’s easy to get to because the flowers don’t have long tubes. And they bloom in late summer, which I think for many of us fills a gap between our summer bloomers and fall bloomers.

The Xerces society has lists of pollinator plants for every region in the U.S. that include bloom time, among other things.

Blooms all season

Here’s a new excuse to buy more plants: you want things blooming all year long. If your garden absolutely explodes in summer but has fewer things in fall, add fall bloomers. Same with spring. Bees need resources as long as they’re active.

Add native plants

Many native solitary bees have relationships with the plants they evolved with. You can even choose plants “backwards”: find a native bee or moth that lives near you, learn what it eats (or what its larvae eat), and plant it, preferably in a “drift” or large group.

Let the story include more than just bees

There are lots of things beyond bees that are a little harder to see, but which we should still colloquially include in “bees love it.” Hoverflies look like bees to deter predators. Sometimes their larvae even feed on aphids. Wasps are fantastic predators of the insects in your vegetable garden. And moths, even the dull-looking ones, represent a critical food source for most birds (i.e. moth caterpillars). Many of these will feed on the same flowers you’re planting for bees.

This family has been frustrating taxonomists—people who study how to describe and classify things—for centuries. It contains between 2,500 to 4,000, depending on who’s counting. This makes it a fairly large family.

Species in this family that you might know

• Strawberries (Fragaria species)

• Hawthorns (Crataegus spp.)

• Blackberries (Rubus spp.)

• Cherry and plum trees (Prunus spp.)

• Apples (Malus spp.)

• Spiraea (Spiraea spp.)

• Serviceberry (Amelanchier spp.)

• Roses (Rosa spp.)

Defining characteristics

The flower arose from a cup! The hypanthium

A defining rose family feature is a structure at the base of flowers that’s made from fused flower parts: petals, sepals, and stamens. The structure, the hypanthium, is frequently described as cup-shaped. It contains the ovary, the female reproductive part of the flower.

A more familiar image might be a pear. If you cut a pear in half the long way, the core (with the seeds) is the ovary, and most of the pear’s flesh is hypanthium tissue. Apples, too.

So for “cup-shaped” to be useful, we need a pretty broad definition of cup. Urn, vase, goblet, etc. Flowers in this family arise—or arose, if the mnemonic helps—from these structures.

Other families’ flowers also have hypanthiums. You’d use this in combination with other features to make an ID.

Flowers

Rosaceae flowers usually have five petals and five sepals, or leaf-like structures at the base of the flower. Flowers are radially symmetrical, which means you can divide them in equal halves in multiple ways. They have whorls of stamens (the male part of the flower, which look like tiny shoots) around their interior.

A “gotcha”: Sepals and bracts

Some plants, such as strawberries, cinquefoils, and avens, have five sepals and five (or more) bracts, or leaflike structures, that make up the part of the flower that protects the petals. I’d like to shout from evolution’s peanut gallery that these are sometimes difficult to tell apart. For example, on Virginia strawberry, you’ll see what seems like a whorl of ten green leaflike “things.” These are sepals and bracts. The sepals are broader, the bracts narrower.

Another “gotcha”: Rose vs. buttercup family flowers

The buttercup family (Ranunculaceae) features a few plants that might appear like rose family plants. For example, plants in this family have open flowers with lots of stamens, and many appear to have five petals. (Often the petals are actually sepals, but you wouldn’t know just from looking.)

However, buttercup family plants don’t have the hypanthium or stipules. Buttercup flowers also tend to have sepals colored like their petals.

Alternate leaves with stipules (an almost-leaf at the base of the leaf stalk)

One useful identifying feature for this family are little leaf-like growths, or stipules, at the base of the leaf stalk (petiole). Sometimes this looks like a leaf that didn’t quite get going, and other times it’s more like little wings on both sides of the petiole. Stipules are prominent in roses, strawberries, and blackberries.

Unfortunately, and confusingly, stipules also can be subtle or fall off entirely, especially on mature foliage. Stipules that fall off as leaves develop are called caducous. This is common in black cherry (Prunus serotina), apples (Malus spp.), and pears (Pyrus spp.), among others

The vast majority of rose family plants also have alternate leaves, where leaves alternate up the stem instead of being across from one another (which would be opposite).

Many species have compound leaves, where a leaf is actually made up of stems and leaflets. What this means for an aspiring identifier is that leaflets might appear opposite, but leaves—the whole structure with leaflets and their stems—are usually alternate. Unfortunately, leaflets look almost exactly like leaves. Botanists distinguish them based on the placement of buds, or shoots that haven’t developed yet. Leaflets don’t have buds, while leaves have them at their base.

Most rose family leaves are also serrated, or have “teeth,” like a saw.

Taxonomists are still working on classifying this family

There’s quite a lot of debate on how many species this family contains. The genus Rubus, for example (blackberries, raspberries, dewberries, etc.) contains either hundreds or thousands of species. There’s no consensus. Crataegus, Hawthorns, have somewhere between 200 and 1000 species.

As an illustration, I submit this exchange about Himalayan blackberry identification from iNaturalist’s forum. One commenter, Dr. Barbara L. Wilson, offers this very clear explanation for the confusion (emphasis mine):

Here’s the problem with the European Blackberry Complex…Members of the European Blackberry Complex reproduce in a way that really messes with our species concepts. They mostly set seed asexually. What seem to be distinct individuals are actually clones, and a single clone might cover a whole county or more.

However, blackberries also have sex. They may have sex even with distantly related members of the complex. The offspring of such crosses can look a bit different from the blackberry clones that were already spreading around the area. Are these clonal populations best thought of as different species or just different genetic individuals? How different do they have to be before we name them? Should every slightly different type be called a species? (Some people would argue yes, which is why you have 2000 named dandelion species in Europe.) If not, how much difference is necessary to name a species? This really messes with biologists’ minds. We don’t agree. We probably will never agree.

Value for wildlife

Pollinator plants

In general, Rosaceae is one of the most important families for pollinators. First, they tend to bloom in spring, and prolifically, when few other things are in bloom.

Humans aren’t the only ones that enjoy cherry blossoms. Plants like black cherry, serviceberry, hawthorn, and strawberries are critical, early sources of pollen and nectar.

Rose family flowers are open. You don’t need a long tongue or beak or proboscis (tube-like feeding structure some pollinators use to access nectar, sort of like you had a straw for a mouth) to gather from a rose flower. They’re accessible for all sorts of small insects, including bees, hoverflies, beetles, moths, and butterflies. They’re sort of like a big box store for pollinators.

For food and shelter

Rose family fruits feed all sorts of birds and mammals–including humans. For example, here in the forests of the U.S. northeast, black cherry (Prunus serotina) is a pillar of the ecosystem. Its fruits are eaten by dozens of birds, including robins, cedar waxwings, and wild turkeys, as well as by mammals like foxes, bears, and raccoons.

This is also a critical host family for butterflies and moths, and therefore by extension, animals that eat caterpillars. The Prunus genus, made up of cherries and plums, ranks among the most important supporters of native northeastern caterpillars—that is, either potential moths and butterflies or potential food for birds, depending on your perspective.

Hundreds of butterflies and moths specialize on plants in the Rosa genus (that is, actual rose plants). Virginia strawberry (Fragaria virginiana) is a fantastic caterpillar host in groundcover form, supporting something like 75 species.

Value to humans

Like animals, we’re big fans of eating this family. For example, we grew 23.1 million metric tons of pears in 2020. Other Rosaceae fruits are nearly as popular: apples, strawberries, peaches, blackberries, and so on. Almonds are part of this family, too. We use rose hips for tea and in cooking or baking.

People have a long history of using plants in this family medicinally and still do today. Rose hips are a good source of vitamin C and were even used in Britain during World War 2 when citrus was in short supply. Hawthorn has been used historically in both Europe and China to treat heart conditions. The family member I’ve named several times already, black cherry, has been used to treat coughs. Rose oils, particularly the essential oil attar of roses, are used in perfumes.

One more mention of black cherry, Prunus serotina here. It’s often used for lumber, especially furniture and paneling, because of its red finish.

Okay, let’s talk about (actual) roses

A fact so obvious it’s almost not worth writing is that we like to put plants in this family in our garden and look at them. We appear to have climbed down from the trees and immediately, evolutionarily speaking, begun cultivating roses. There’s evidence that people in China were cultivating roses 5,000 years ago. But the features we breed for today, such as doubled petals, tend to come at the cost of pollen, nectar, and hips. That is, we breed out the stuff that wildlife depends on.

It’s unfortunate that cultivating something aesthetically beautiful costs something ecologically beautiful. Our symbol of beauty’s a bumblebee’s boarded-up storefront.

But I’d like to think combining these perspectives gives us something even nicer. Wild rose flowers are amazing. And then you can slide in the lens that helps you imagine the birds, moths, and bees they sustain. That’s a plant that blows back one’s proverbial hair. And if my wife reads this far, some men do like roses for anniversaries, so long as they’re plantable and wild type.

Sources

• Bringing Nature Home, Doug Tallamy (2007)

• Chapter 8. Rosaceae: The rose family | UC Riverside

• Evolution of Rosaceae Fruit Types Based on Nuclear Phylogeny | Molecular Biology and Evolution | Oxford Academic

• Identification of Roses, Leaf stipules | Violets and others

• Families-Rosaceae | Ohio Plants

• Himalayan Blackberry Confusion | iNaturalist Community Forum

• Rosaceae | Purdue Horticulture & Landscape Architecture

• Rosaceae lecture | Ohio Plants Online, YouTube

• Stipule | Master Gardeners of Northern Virginia

• Stable temperatures

• No wind (unless you point a fan at them)

• Much less intense light

• Fewer pests

• Regular watering

Under these conditions, plants skimp on cell walls. They skimp on stem length. Leaves don’t bother with the waxy coating, or cuticle, that protects them from very bright light. And thus Mike Birbiglia’s observation about indoor cats also applies to the plants we start indoors.

Before we take indoor-started seedlings out to the vegetable garden, we need to acclimate them to what it’s like out there. Plants have the incredible capacity to morph their physiologies in response to environmental conditions. Sort of like if you could force grow a fur coat each winter. The fun technical term for this is thigmomorphogenesis, coined by M. J. Jaffe in a 1973 paper describing how some plants respond if you rub their stems.

The hardening process

Hardening, or hardening off, refers to plants getting literally harder and sturdier. We put them through a sort of plant boot camp.

This transition generally takes about two weeks for seedlings. (Houseplants may appreciate more time, since they’ve been inside for months, not a few weeks.)

I’ll give two processes, which you can think of as defining a spectrum from “cautious to the point of micromangerial” to “I don’t have time for this.”

The micromanagey process

• Days 1-3: Leave seedlings in a shady spot for an hour or two, then bring them back inside. Important: Shade outdoors is more intense than most grow light setups. You’re already exposing them to more light than they’ve been getting inside.

• Days 4-7: Introduce morning light, which is less intense than afternoon light, and increase the total time they’re outside. Move them back to the shady spot in the afternoon. Leave them outside longer each day, too. By the end of the week, they can be out for most of the day.

• Day 8-10: Include afternoon sun.

• Day 11-14: Put them out earlier and leave them out later so they get used to cooler night temperatures.

The “I don’t have time for this” process

• Day 1-7: Find a spot that gets a few hours of morning sun and is shaded all afternoon. If you don’t have that, find a spot that’s shady all day. Leave them there during the day and bring them in at night

• Day 8-14: Don’t bring them in at night unless it’s going to be below 50 degrees.

Obviously, you could put them in the ground on day 8 with this method. The only reason I suggest leaving them in pots is because we tend to time things so that they go into the garden at the earliest possible, and therefore just-barely-warmest, time. The extra week in pots gives you a little flexibility. If you get an unexpected cold night, you can still bring them in.

A number of caveats and nuances

Location, location, etc.

Choose location(s) that help you manage all the various environmental factors seedlings will be exposed to.

• Morning sun is less intense

• Afternoon sun is more intense

• Outdoor shade is often brighter than under your indoor grow lights

• You would likely prefer that rabbits or squirrels not have easy access to them

• Wind can be very damaging for tender, unhardened seedlings

Light intensity

It’s useful for us to understand a skosh about light in different contexts: grow lights, outdoor shade, outdoor direct sun. You’ll see light measured in a few different ways. There’s “foot candles,” which is essentially how many candles’ worth of brightness something is. Scientists might measure light in µmol/m²/s¹, or micromoles per square meter per second, or how much light is available for photosynthesis.

But since most of us aren’t measuring light, what’s important is that the shade under your oak tree is usually brighter than your grow lights. This is because the atmosphere diffuses sunlight—that is, scatters it, and quite vigorously—into shady spots. And while it’s counter intuitive, the amount of light being scattered into the shade is much brighter than the amount produced by grow lights.

Watering and rain

You may need to water more often outdoors. Wind and sun tend to dry plants out more than sitting on a shelf with a grow light.

Rain is fine if it’s light. If it’s going to rain a lot, bring seedlings inside. Plants in small containers can easily get waterlogged and even physically damaged. Remember, they haven’t finished thigmomorphing yet. A downpour can crush weak stems.

Don’t water if they don’t need it. Stick your finger into the growing medium and check for moisture just below the surface.

Look out for signs that you’re pushing seedlings too hard

The most common sign that plants aren’t ready for the amount of light they’re getting is white spots on leaves. The leaves may turn light gray or white (bleaching). You can certainly kill seedlings this way if you’re not careful.

Some leaves may develop red, purplish, or orangey colors. This is fine. These pigments (flavonoids) protect plants from too much light. The most recognizable of these are likely anthocyanins, which cause the reddish color that the leaves of pepper seedlings often take on, even indoors.

When is it time to harden off plants?

1. When your seedlings are ready

2. When the conditions outdoors are ready

The general rule is to wait until seedlings have at least 2 sets of true leaves. That is, not the first leaves, or cotyledons, that emerge. We want the next sets, which look like the plant’s mature leaves.

But the conditions outdoors have to meet the plant’s minimum requirements. You can’t start zinnias indoors and then try to harden them in April in New England. Zinnias like warm weather and won’t be thrilled about nights that might still drop into the thirties.

It helps to know your last frost date. But more than that, it helps to have done some research about what your plant will tolerate. Some plants tolerate cold. Others need nighttime temperatures over 50°F / 10°C.

Some plants are better off started outside

For example, you can generally put in peas and onions as soon as you can manipulate your soil. That lets you skip the entire hardening process. Root vegetables (carrots, parsnips, radishes) tend to do better planted directly, since they react poorly to root disturbance.

Many cut flowers, even warm-season ones, have plenty of time to mature even if you wait and start them outdoors. This includes cosmos, zinnias, marigolds, sunflowers, and nasturtiums.

And I know one gardener who only starts zucchini in late July, after the squash borers have completed their life cycle.

Native plants are often best started from seed. One of the nicest things about native plants is that they evolved to grow in places with harsh winters. You can scatter them in fall or use one of the numerous guides to milk jug winter sowing. We generally harden things only when we need to create the right (artificial) conditions for something to grow where we live.

Bonus nerdery: What’s actually happening during hardening?

A few different things, some of which are quite visible. First, plants produce a waxy layer over their leaves (and green stems and fruits) called a cuticle. The cuticle is a critical adaptation to all sorts of environmental stresses, one of which is limiting the harmful effects ultraviolet radiation can have. For example, plants may reflect UV rays or absorb them in a way that prevents them from affecting tissue.

They also produce the flavonoids, including anthocyanins, that we mentioned earlier.

Plants harden their cell walls. They produce more lignin, the substance that makes wood woody. It functions a little like biological cement that fills in gaps between cellulose in cell walls. Imagine dunking a pillowcase in glue and letting it dry. That’s sort of what’s happening during hardening off to stems and leaves.

A few other things happen, too, including faster root growth and changes in energy storage and water use.

Like other members of the arum (Araceae) family such as peace lilies, it can burn carbohydrates stored in its roots to warm the air right above it as much as 20 degrees (thermogenesis). This allows it to melt its way up through still-frozen ground and move its bloom time to very early in the year.

It comes up flower first, leaves still furled spear-like. The hood (spathe) is a fleshy purple or maroon with green or white mottles. It protects the flower cluster (spadix). The appearance probably contributes to attracting early season flies, as does the smell, which one author apparently described as combining “skunk, putrid meat, and garlic.”

Native range and habitat

Native across the northeastern U.S., the upper midwestern states, and southern Canada. Extends south through North Carolina and a single sighting in South Carolina. It’s much rarer in the southern states, since it’s not adapted to hot summers. The northern U.S. and southern Canada also contain more of its natural habitats. See a range map on bplant.org.

Its habitats tend to have a lot of groundwater. It wants the wet muck of waterways, swamps, and seeps (places where groundwater naturally comes to the surface). It also grows in wet deciduous woodlands (that is, woodlands where trees drop their leaves). It’s even evolved so that its roots can physically contract, which helps it anchor itself into the soil. This force is strong enough to pull the entire stem beneath the ground.

These types of habitats, consistently moist and cool, are much more common in the northern part of its range. In the south, it’s likely limited to higher elevations, where it’s cooler and moister.

Prefers at most partial sun and tolerates fairly deep shade. Does not like direct sun.

Interactions with wildlife

Pollinators

As your resident goth forest plant denizen, eastern skunk cabbage is of course pollinated by things like flesh flies, carrion flies, carrion beetles, and gnats. Its, uh, “floral scent” includes compounds that make it smell like rotting protein to attract them.

Eastern skunk cabbage blooms when very few other things do, as early as February and March in some places. In addition, as we mentioned, it’s able to warm the air inside its hood. This means it provides food and shelter during a critical time of year, especially in the cold places where this plant is found.

Spiders sometimes build webs inside the spathe to take advantage of insects looking for a warm place to rest.

Host plant

Hosts a few species of moth, including the ruby tiger moth (Phragmatobia fuliginosa) and cattail borer moth (Bellura obliqua). These don’t specialize on eastern skunk cabbage, though. The ruby tiger moth is a generalist, and the cattail borer is more narrowly focused on wetland plants (such as cattails).

Mammals

Deters most mammals. Its leaves contain razor sharp calcium oxalate crystals, the same substance that makes up kidney stones. Eating it apparently causes a burning sensation in your mouth and throat, as well as vomiting and diarrhea.

Still, animals emerging from hibernation will eat it in desperation. Many sources mentioned black bears and snapping turtles eating it when there’s not much else around.

How to identify it

We’ve already touched on its flower structure. This has 2 major parts:

• The spathe is the hood that protects the flowers. (This is the same structure as the white hood on a peace lily.) On eastern skunk cabbage, it’s a mottled purple, like someone has only applied a single coat of paint.

• The spadix is a sort of fleshy-looking flower spike. The yellow flowers are small and don’t have petals

The whole flower structure is about half a foot tall, though the spadix itself is a few inches shorter. It blooms before its leaves unfurl.

The leaves come up with the flower structure, but they stay furled, spear-like, until late spring. They’re big, up to 2 feet long and a foot wide. They’re dark green, deeply veined, and look like cabbage leaves. Mature plants have four or more leaves per crown, immature ones fewer.

The petioles, or stalks that leaves attach to, are thick and stick out at an angle. The leaf structure forms what looks like a vase, and the plant really does look like a giant head of cabbage growing out of the ground.

By late summer, the leaves have withered away. At this point, the fruit is beginning to mature. It’s formed from the spadix. Each of the little flowers forms a small fruit, and they fuse together into a fleshy, lumpy mass, like something from a Tim Burton fever dream. The mass is ovular, dark purple to black, scaley-looking, and smells like rotting fruit. This compound fruit is called a syncarp.

How it spreads and grows

Reproduces only by seed. The syncarps we discussed rot and fall to the ground, allowing skunk cabbage to colonize areas. Floods may also disperse seeds.

Skunk cabbage lives for a long time (20+ years). However, it doesn’t handle when water systems are disturbed (e.g., by drainage). This makes it an indicator of if a wetland has a healthy hydrology.

Skunk cabbage isn’t technically spring ephemeral, since it doesn’t complete its aboveground lifecycle in the spring. It sort of rhymes with this way of growing, though, since it completes its bloom cycle very early in the year.

Uses by people

Lots of Native American peoples made use of skunk cabbage. As a food, it needed to be processed to be edible. For example, one report suggests that to eat them as vegetables, they had to be boiled, and the water changed at least 3 times during the process.

There are far more examples of its being used medicinally (not surprising, given that it may’ve been a pain to prepare, and even more painful to eat). Apparently both the Delaware and the Mohegans also used it for epilepsy. They may have passed this along to American doctors, who used it for this and to treat a few other diseases, including scurvy.

The roots were often dried and used to treat respiratory problems, such as coughs, colds, and tuberculosis.

Sources this is based on

• Skunk cabbage, Symplocarpus foetidus – Wisconsin Horticulture

• 7.2 Seeps | ‘Good Forestry in the Granite State: Recommended Voluntary Forest Management Practices for New Hampshire’

• Eastern Skunk Cabbage (Symplocarpus foetidus) - bplant.org

• Plant of the Week: Eastern skunk cabbage | USDA

• Skunk Cabbage (Symplocarpus foetidus)

• BRIT - Native American Ethnobotany Database

• Skunk Cabbage Flowers: The Heat is On

• Floral scent of eastern skunk cabbage (Symplocarpus foetidus: Araceae) - ScienceDirect

• Symplocarpus foetidus | Indiana Nature

Wild leeks are spring ephemerals, or plants that emerge quickly when the weather begins to warm up and then die back (partially).

Spring

They produce their first leaves before trees have leafed out. Plants produce 2 or 3 leaves. These are long, between 4-10 inches each, and thickest in the middle. They’re egg-shaped if an egg could be 4-10 inches long. The leaves are light green. They look a little like tulip leaves.

They also smell like garlic.

The narrow base that attaches the leaf to the bulb (petiole) is red. You might not be able to see this if the plant is surrounded by leaf litter, though.

Summer

Leeks’ leaves die back as the trees begin to shade the ground. They then produce a single flower stalk (scape) that rises about a foot.

The bloom looks like a sphere of little white flowers. The spheres can contain 20 to 30 little flowers. Each flower:

• Is white with a yellowish green center

• Has 6 petals (actually a tepal, a structure where petal and sepal are indistinguishable)

• 6 stamens (where the pollen is)

• Connects to the central stalk. This connecting stalk is a pedicel.

The flower structure, where little flowers all connect back to the same stalk on pedicels, is called an umbel. It’s characteristic of the Amaryllidaceae, the garlic (or allium) family.

Last week, I wrote that umbels are main features on Apiaceae, the carrot family. Both are true—and since there are something like 600 plant families, it’s still fairly distinguishing. Allium umbels tend to be spherical, and carrot umbels tend to be flat-topped.

Fall and winter

The flowers are replaced by seeds. These are shiny black spheres that may stick around all winter on the flower stalk.

Bulbs

Wild leeks have bulbs, much like onions or shallots. Wild leek bulbs are an inch or two long, and each plant has a few of them (2 to 6).

The bulb, along with the flowers and leaves, smell strongly like onions or garlic. Unsurprisingly, people like eating them.

How it spreads and grows

Wild leeks grow slowly. Seeds can take 2 years to get started. This is because they need a warm, moist period for their roots to grow and then a cold, moist period for shoots to grow.

In addition to seeds, wild leeks reproduce through division. Their bulbs produce offsets, or clones, which become new plants. In the garden, you can divide them manually. Do this in spring before they put on leaves or in the fall.

Both seeds and offsets produce new plants right next to their parents. This means that leeks tend to grow in thick colonies.

Planting wild leeks in your garden

If you’re trying to grow them, you can sow them outdoors and be very patient, or you might need to simulate these periods. For example:

• Start them somewhere warm (60 days). This simulates the spring and summer, after they’ve fallen off the plant. (Remember that they can stay on the mother plant all winter.)

• Move them to the fridge (90 days) and keep them cold and moist. This simulates the next winter

Of course, a lower maintenance approach would be to plant them, mark where you planted them, and ignore them for a year or two.

After they germinate, it can take another 5 years or more before they flower for the first time.

Natural habitat

Wild leek grows in the rich, moist soils of deciduous forests (that is, made up of trees that drop their leaves for winter). As spring ephemerals, they need to put on leaves and gather sunlight before the trees produce leaves (and therefore shade) in spring. This is a very cool adaptation where a shade plant is temporarily a sun-loving plant.

Where it’s native

Wild leek is native across central and eastern North America. This includes Manitoba through Nova Scotia in Canada, and North Dakota through New England south to Alabama and Georgia in the U.S.

Wildlife associations

Pollinated by many different types of bees: bumblebees, mason bees, sweat bees, and masked bees.

A few different types of insects eat wild leek, including thrips and onion plant bugs. However, like most alliums, they’re not great host plants for insects. They contain defensive, sulfur-containing chemicals that deter insects and microbes that might want to eat them.

Some sources say that the onion scent seems to deter deer and rabbits from eating wild leeks. Others say deer are happy to eat the young, tender foliage in spring.

Turkeys eat seeds in the fall.

The leek moth (Acrolepiopsis assectella) feeds on various Allium species. It may eat wild leeks, though it seems to prefer cultivated crops (garlic, onions). It’s invasive in North America.

Uses by people

People eat both the leaves and bulbs, which taste like onions and are used in soups and salads.

In some places (such as Quebec), this plant has been overharvested and is endangered.

Indigenous people used it for a variety of reasons, including just eating it because it tastes good. It also could be dried and stored over the winter.

It was also used medicinally. The Cherokee and Iroquois may have used it as an emetic.

Sources this is based on

• Allium tricoccum (Wild leek) | Native Plants of North America

• Allium tricoccum (ramps, wild leek): Go Botany

• Allium tricoccum (Wild Leek): Minnesota Wildflowers

• allium triccocum | BRIT - Native American Ethnobotany Database

• Dion, Pierre-Paul, et al. “Late canopy closure delays senescence and promotes growth of the spring ephemeral wild leek (Allium tricoccum).” Botany, vol. 95, no. 5, May 2017, pp. 457+

• Ramps (Allium tricoccum)

• Ramp (Allium tricoccum) | bplant.org

• Understanding the defense mechanism of Allium plants through the onion isoallicin-omics study | PMC

• Wild Leek (Allium tricoccum)

…when I, returning from walking the dogs or a trip to the store, bound back into my house and shout, it’s starting! It’s starting! What’s dada doing, my two-year-old asks. Oh, my wife says, he saw a crocus or something.

I did see a crocus, and also a snowdrop, and a few other common symbols of spring warming up its engine. But a lot of other things are waking up, too. Here are a few.

You came back!

Every year, I feel a pinch of exhilaration when things I planted re-emerge. Somehow it always feels impossible that they’ve survived another winter.

And yet here’s new growth from the crown of clustered mountain mint (Pycnanthemum muticum) pushing up through leaves and mulch. People often claim that “bees love” certain plants, which sometimes just means, “I see bees on that plant.” But in this case, they actually do. Clustered mountain mint blooms for months and produces tons of nectar.

I also see the sword-shaped leaves (gladiate, like the Roman short sword, the gladius) of Blue flag iris (Iris versicolor) poking up. Blue flag is toxic to mammals. This makes it a nice addition to suburban yards where out-of-whack ecosystems produce large deer and rabbit populations. It hosts a few species of moths and sometimes attracts hummingbirds.

A sort of “fun” ritual that I assume most gardeners go through is seeing emerging basal foliage and wondering, what did I put there again? For example, I can’t remember which Rudbeckia species is emerging in one corner of a bed. Is it brown-eyed susan (Rudbeckia triloba)? Maybe? There’s brown-eyed susan somewhere over there.

I’ve always enjoyed the more compact, tighter blooms on this plant. It’s unlikely that I’ll get to see the silvery checkerspot, which lives on Rudbeckia Triloba but is probably gone from Massachusetts. But the orange-and-black pearl crescent isn’t. Maybe I’ll see one of those.

I had assumed that this common yarrow (Achillea millefolium) hadn’t survived the previous year. It hadn’t looked so good in late summer. But one should never assume yarrow hasn’t survived. It is an ambitious plant.

We usually talk about plants at the species level, but yarrow is a species complex. It has multiple subspecies, some of which you can only tell apart if you can count its chromosomes. (I can’t.) Some of the subspecies are native to the U.S., some to Europe, and others to Asia. As a vaguely irked writer for the U.S. Forest Service put it, “the intricate pattern of morphologic, geographic, and ecologic variation within the species has frustrated all efforts to organize an intraspecific taxonomy on a circumboreal or even a strictly North American basis.”

Not a plant, but very fuzzy

Around this time, as the sun warms patches of dirt in my backyard, fuzzy ground-nesting bees emerge from a collection of little burrows. I believe these are unequal cellophane bees (Colletes inaequalis).

Where I live, unequal cellophane bees emerge before bumblebees or honeybees. I like to think they fill an important ecological niche, pollinating the maples and willows that are starting to bloom.

Plants out of place

Similarly fuzzy are the big, yellowgreen leaves of mullein (Verbascum thapsus), a plant native to parts of Europe, Asia, and northern Africa. Mullein was perhaps introduced as a medicinal herb or a fish poison. It’s still popular with foragers today.

In some U.S. states (Texas, California, Hawaii), mullein elbows native plants out of meadows and forest openings. This is unpleasant for both the native plants and the wildlife that evolved to depend on them. For this reason, I usually pull it. While it’s not on Massachusetts’s list of invasive plants, the Mass Invasive Plant Advisory Group does write that “its occurrence in critical habitats (especially limestone cliff communities) is of concern.”)

Thousands of little sprouts are coming up along the edge of a nearby wetland. These, I remember from last year, are garlic mustard (Alliaria petiolata) (along with a couple types of dock [Rumex spp.]) Garlic mustard actually is on the Massachusetts invasive species list. It produces chemicals that suppress soil fungi that support forest plants (Or with more jargon: it is allelopathic, and the chemicals it produces suppress arbuscular mycorrhizal fungi). This allows it limit competition and colonize big parts of the understory. It’s native across Europe, northern Asia all the way to China, and northwest Africa.

Another plant that likes this wetland edge is winter creeper (Euonymus fortunei), an east-Asian native. Winter creeper is on invasives lists across the eastern U.S. (though not here in Massachusetts yet). Like English ivy, it’s evergreen, and therefore already photosynthesizing, which gives it a head start on a lot of our natives. It can grow as a ground cover, smothering seedlings and smaller plants.

Like many plants out of place, this one is an “escaped” ornamental. You’ll still find varieties of it sold in garden centers.

Species in this family that you might know

• Vegetables like carrots, celery, and parsnips

• Edible herbs like dill, fennel, cilantro, and parsley

• Spices such as coriander, cumin, caraway, anise, chervil, asafoetida, and lovage

• Poison hemlock (Conium maculatum) and the even-more-toxic water hemlock (Cicuta spp.)

• Giant Hogweed (Heracleum mantegazzianum), a plant whose sap combined with sunlight can cause a very bad skin burn (phototoxic sap)

• Queen Anne’s lace (Daucus carota), ancestor of the cultivated carrot.

• Golden Alexander (Zizia aurea), popular with native plant gardeners in the eastern U.S.

Note: Queen Anne’s lace, while edible, looks a lot like poison hemlock. Don’t eat a plant if you’re not sure what it is!

Common characteristics

Flowers

Apiaceae are best known for their flower shape. Their umbels consist of flowers on stalks that connect to a central point, like the ribs of an umbrella. Umbels can have one set of stalks (simple) or multiple (compound) each ending in a little mini umbel.

The individual flowers are usually small and have five petals and five stamens each. They’re most commonly white, yellow, or pink. Each flower has 5 petals and 5 stamens. The inner flowers on an umbel are usually symmetrical along multiple axes. This is also called radial symmetry or actinomorphic.

That said, the outer flowers are sometimes larger than the inner ones, as the image of a Queen Anne’s lace umbel shows. The larger flowers help attract pollinators and are only symmetrical along one axis (zygomorphic), such as vertically.

I should note: alliums (wild leek, garlic, the big ornamental ones you see in gardens) also have umbels. But those tend to be shaped like spheres.

Fruits

Apiaceae plants produce a dry fruit that, when mature, splits into 2 single-seed segments. The individual segments are called mericarps, and the whole fruit is called a schizocarp.

The seeds often contain essential oils, which help protect them from herbivores, among other ecological functions. As a bonus, we think they taste and smell good. The oils are what provides the flavors we like in dill, coriander, fennel, anise, cumin, and more.

Leaves

Most family members have alternate leaves, a pattern where leaves alternate on which side of the stem they grow. Other types of plants have opposite leaves, which grow right across from each other.

Another reliable identifying characteristic is that the base of the leaves in this family tend to shield or sheath the stem. This is most obvious on something like celery from the grocery store–think of how the bottom part of the stalks widens and cups the other stalks. It’s less clear on dill, where the stems are much smaller.

Leaf shape is not a great tool for identifying things in Apiaceae (though it may help with specific species). Some of the best known Apiaceae, such as hemlock and carrot and dill, have feathery-looking leaves (pinnate). These are also often compound, meaning broken into segments. But the family also includes plenty of species with other types of compound leaves, and still others with simple leaves, including leaves shaped like ovals, leaves with lobes, and spiny-looking leaves.

As with the fruit, leaves also produce and store essential oils. Crushing the leaves of parsley or cilantro creates smells we like.

That said, don’t crush a plant’s leaves if you’re not familiar with it. Some members of Apiaceae, for example, are extremely toxic.

Toxicity and phototoxicity

This family includes some plants that are extremely poisonous if you eat them. Socrates is said to have died from drinking a potion of poison hemlock, for example (Conium maculatum). Other poisonous Apiaceae include water hemlock, spotted cowbane, and fool’s parsley.

Quite a few Apiaceae plants can also cause serious skin inflammation if you touch them and then are exposed to sunlight (phototoxicity). To be clear, this isn’t like poison ivy: just brushing against them might not cause a problem. It’s their sap and essential oils that cause the problem, so you’d need to physically damage the plant. Having said that, crushing a leaf or bruising a stem might not require much force.

Wildlife value

For shelter and food

Many insects use Apiaceae plants as hosts for their larvae. Perhaps the best known are the swallowtails. Black swallowtail (Papilio polyxenes), for example, lay eggs on a variety of plants in the family. You might even find them on dill and parsley in your vegetable garden. (I recommend leaving them, even at the cost of some herbs! They’re very cool!)

Swallowtails (and others that feed on Apiaceae) are specially adapted to feed on Apiaceae in spite of the essential oils that deter other herbivores. Many other butterfly and moth larvae can do this, too. For example, poison hemlock has its own specialized moth companion, Agonopterix alstroemeriana (the hemlock moth). The parsnip moth, a European species, feeds on hogweed, parsnip, and fool’s watercress.

A variety of other insects, including flies, beetles, aphids, and weevils also specialize on Apiaceae. Examples include the carrot fly (Chamaepsila rosae) and the celery fly (Euleia heraclei).

What these insects generally trade for their evolved ability to eat Apiaceae is that they don’t eat anything else. They depend on Apiaceae. This is a good reason to include plants in this family in your garden, even though Apiaceae species don’t have the showiest flowers. This can take a little research, since they’re not common horticultural plants. A few U.S. natives include:

• Golden Alexander (central and eastern U.S. and Canada)

• Rattlesnake master (most of central and eastern U.S.)

• Brewer's angelica (California and Nevada)

• Rose angelica (Colorado, Idaho, Montana, Utah, and Wyoming)

On the other hand, birds and wildlife that eat Apiaceae seeds aren’t specialists. Finches, chickadees, juncos, cardinals, nuthatches, and other generalists include them in their diets.

As pollinator plants

The umbel flower structure makes pollen and nectar easy to get for short-tongued pollinators. This means they attract a range of insects such as hoverflies, wasps, beetles, and parasitoid wasps. A parasitoid wasp is one that hunts other insects to lay their eggs on them. Probably the most well-known example for gardeners are wasps in the family Braconidae, which lay eggs on tomato hornworms (those big, green worms that eat your tomatoes).

Bees use Apiaceae, too–especially smaller, solitary bees. Like other small insect pollinators, they may not be able to get to the nectar of flowers with deep, long tubes. The accessible flowers of Apiaceae plants are much easier for them to work with.

Value to humans

We use plants in this family as food, such as carrots, celery, and parsnips. We also like the flavor of the essential oils in the leaves and seeds, and we use them as herbs and spices: coriander, dill, cumin, etc.

They may also make good companion plants for vegetable gardens. In studies of how flower strips near crops reduce pests, Apiaceae plants tend to be one of the best-performing families. They do this by attracting a variety of beneficial insect predators. Many species of hoverfly, for example, prey on aphids, and may be attracted to food crops by the flower strips. That said, the results also suggest that a diversity of plants is critical for making flower strips work.

(Apiaceae were only some of the plants in the study’s flower strips. It’s a good idea to mix families when you create habitat for beneficial insects.)

A few have also been used for incense and perfume. For example, a few plants in the Ferula genus have been used to produce galbanum. These plants, which mainly grow in northern Iran, release a scented substance that’s a mix of gum and resin when damaged. Galbanum has a long history of human use and even appears in the bible (Exodus 30:34) as part of a formula for incense: “gum resin, onycha and galbanum—and pure frankincense, all in equal amounts.”

Sources

• Apiaceae | Elizabeth’s Wildflower Blog

• Apiaceae lecture | Ohio plants online (YouTube)

• Angelica breweri (Brewer's angelica) | Native Plants of North America

• Angelica roseana (Rose angelica) | Native Plants of North America

• Carrot Rust Fly (Chamaepsila rosae) | iNaturalist

• Celery fly | iNaturalist

• Chemical composition and biological activities of essential oils of seven Cultivated Apiaceae species | Scientific Reports

• Eryngium yuccifolium (Rattlesnake master) | Native Plants of North America

• Evolution of Specialization in Insect-Umbellifer Associations

• Galbanum - Wikipedia

• Highly diverse flower strips promote natural enemies more in annual field crops: A review and meta-analysis | ScienceDirect

• Intro to the Carrot/parsley Family - Apiaceae | Botany and Beer (YouTube)

• Schizocarp, Mericarp |McGill University

• Phytophotodermatitis and the Giant Hogweed | Office for Science and Society - McGill University

• Zizia aurea (Golden zizia) | Native Plants of North America

  
  

Poison ivy changes shape and color as it grows. It can grow as a shrub, a vine, or a groundcover, and its leaves take many different forms. (One paper I looked at identified 6 different variations on leaves!)

All of this makes identifying it more difficult than you’d like, especially since touching any part of the plant can cause a skin condition called contact dermatitis. Its symptoms are itching, redness, and oozing. Some people are immune–but immunity can fade with repeated exposure. (More on this later.)

Leaves of 3

You’ve likely heard the phrase, “leaves of 3, let it be” as a way to identify poison ivy. This is vaguely helpful, but lots of plants look like they have leaves in groups of 3.

Poison ivy’s pattern, which holds true across leaf variations, is 2 leaflets opposite each other and 1 larger leaflet between these 2. The larger one is perpendicular to the pair. A small length of stem separates the larger leaf from the pair.

Technically, this whole structure is a compound leaf. (That’s why I’m writing leaflet instead of leaf—each of the 3 is a leaflet.) A long shoot connects the compound leaf to the main vine (the petiole).

The compound leaves alternate along the main stem. That is, you won’t find them directly across from one another.

Poison ivy leaflets vary a lot. They can be lanced-shaped (lanceolate) or more like ovals (ovate). They may have lobes that make them look like mittens, they might have smooth edges, or they might have a few “teeth” on their edges. They can also be a range of colors–many shades of green, and red when they’re young or in fall.

“Hairy” vines

Poison ivy can grow as a vine, climbing more than 100 feet. When it does this, it produces lots of roots that help it attach to whatever it’s growing on. This gives it a distinctly hairy appearance, especially if it’s a larger vine.

(These are called adventitious roots, which just means roots produced by non-root tissue. Lots of plants have them, and they do a variety of things—take in water from the air, create new plants (like strawberries), and even parasitize other plants.)

Other vines also create these, so the “hair alone” doesn’t mean a vine is poison ivy. That said, poison ivy does have an especially hairy look compared to vines like Virginia creeper.

Poison ivy vines also typically grow straight up. This is different from something like bittersweet, which tends to wind around what it’s growing on.

Flowers and fruits

Blooms between May and July. Flowers are small, greenish yellow. They form in clusters where the leaf branches off from the main vine (the axil). (Remember that the “leaf” is a compound structure of 3 leaflets plus a stem that connects to the main vine.) Each flower has 5 petals that curl backward and 5 yellow stamens.

Each flower forms a fruit that looks like a small berry. It’s technically a drupe, since it contains a pit that encases a seed. The fruit is whitish tan. It matures over the fall and will last through winter (unless a bird eats it).

How it spreads and grows

Poison ivy does well in a huge variety of conditions, spreads multiple ways, and can change its “form” (e.g., groundcover to vine) to take advantage of its environment.

The main way it spreads is through its roots (rhizomatically), which send up new shoots every so often. This allows it to act as a ground cover.

It also spreads through seed. Birds eat its berries and then disperse them (i.e. they poop them out). This is why you’ll often see new vines starting at the base of a tree–it likely came from a bird sitting on a branch above, along with a little bit of fertilizer.

It does well in a variety of light conditions. Tolerates shade and full sun.

It also tolerates a range of soils, from moisture-retaining clay soils to quick-draining sandy soils. For example, though it likes rich forest soils, it’ll also grow on sand dunes in salty air.

Finally, poison ivy can regenerate from a piece of vine that’s only an inch or two long. This is one reason that removing it can be a chore. If you leave a piece of the vine in the ground, it can regrow.

Where it’s native

Across all of the central and eastern U.S. The only places you won’t find it in the U.S. include the desert and most of the west coast.

Also native to southern Canada and Mexico south to San Luis Potosi.

Natural habitat

It likes forest edges and “disturbed” areas, such as when a tree falls in the woods and opens up a patch of light in the forest canopy. Other kinds of natural disturbances include fires, floods, or a large animal trampling something. These let it take advantage of things like extra light, reduced plant competition, and exposed soil.

Humans cause quite a lot of disturbance and create a lot of “edges.” New roads, fences, and hiking trails are all good poison ivy habitat.

Where I live in suburban New England, poison ivy shows up beneath anything a bird might sit in. It grows beneath trees and fences in the park, along the edges of the nearby wetlands, and along the roadside.

Wildlife associations

Humans and some other primates are the only animals affected by urushiol, the oil that causes dermatitis. For others, the plant is a critical food source.

Poison ivy berries are a critical food in the winter for many, many species of birds. These include robins, black-capped chickadees, brown thrashers, downy woodpeckers, and dozens more.

It’s a host plant for a few moths, including the Showy Emerald (Dichorda iridaria), Dark Marathyssa Moth (Marathyssa inficita), Epipaschia superatalis, and Cameraria guttifinitella. Also hosts other insects, including the poison ivy sawfly (Arge humeralis) and the poison ivy leaf beetle (Aulacothorax melinus).

Deer, mice, and other small mammals browse poison ivy.

It’s pollinated by a variety of insects including bees, ants, and wasps.

Uses by people

Supposedly, some native peoples used poison ivy to address skin conditions like boils or sores that weren’t healing. The Navajo may have used it for poison arrows.

In the 18th century, European physicians had lots of theories about its healing potential. One claimed that drinking it as a sort of tea might address a range of skin problems. Another 19th century physician published a claim that it could treat rheumatism and paralysis.

How poison ivy’s “poison” works

Every part of the plant–leaves, roots, fruit, flowers–is covered with an oily substance called urushiol (pronunciation: yoo-ROO-shee-ol). If it’s absorbed by your skin, you may develop contact dermatitis, an uncomfortable and unappealing rash. It can take more than 24 hours for it to appear. It may appear in other places on your body after that, since the urushiol could be absorbed at different rates. In severe cases, you might have a systemic reaction, where you get a rash in places that never came into contact with the plant.

You can also have a reaction if your dog runs through poison ivy and then rubs against you, or if it gets on your clothes and then you touch your clothes. (Your dog won’t be affected.)

If you know you touched poison ivy, you can wash the urushiol off with water and soap. You have to do this quickly; once it’s been absorbed, washing won’t help.

Poison ivy rashes sometimes ooze. Touching a rash does not spread the urushiol more.

Your doctor might prescribe steroids if you have a very bad case.

Some people don’t have reactions to poison ivy. Unfortunately, they can still develop a sensitivity, especially with repeat exposures.

Sources this is based on

• Poison ivy (Toxicodendron radicans) leaf shape variability | Wiley Online Library

• Toxicodendron radicans| North Carolina Extension

• Biology and Management of Poison Ivy | University of Florida

• How to Identify Poison Ivy | University of Maryland Extension

• Native American Medicinal Plants - Daniel E. Moerman | PDF

• Materia Medica | Ohio memory

• Eastern Poison Ivy (Toxicodendron radicans) - bplant.org

• Winter Birds Love Poison Ivy — Menunkatuck Audubon Society

• Poison Ivy | Illinois Wildflowers

• About Eastern Poison Ivy - Maryland Biodiversity Project

• Moth Photographers Group – Epipaschia superatalis – 5577

• No Ill Nature: The Surprising History and Science of Poison Ivy and Its Relatives | Science History Institute

• Urushiol - Wikipedia

• Everything You Need to Know About Poison Ivy | Des Moines University Clinic

• Includes culinary herbs such as basil, sage, and rosemary

• Popular pollinator garden plants such as lavender, bee balm, catnip, and Russian sage

• Trees in this family include teak and the chase tree

• Other well-known mint family members include coleus, American beautyberry, and deadnettle

Common characteristics

Essential oils

Many mint family plants have leaves with strong, pleasant smells. For example, oregano, thyme, basil, savory, marjoram, and rosemary are all in the mint family, along with, of course, mint.

The smell is from oils, which are held in little sacs on microscopic hairs called trichomes on leaf surfaces. They’re released when crushed or when they’re heated (such as when you cook them). These oils are called essential oils or sometimes volatile oils.

It may seem ironic, but essential oils protect plants by being unpleasant for herbivores to eat.

Square stems

Mint family plants are known for having square stems, though this description sounds more straightforward than it is. It’s also not true for every species in Lamiaceae.

Stems look most square when shown in a cut cross-section. From this view, many species’ stems clearly look square, though with rounded edges. Basil, bee balm, and mint (the plant, not the family) all have extremely square stems.

However, some species have much more subtle edges. And woody stems, such as the ones rosemary or lavender grow as they get older, round off and don’t look square.

Opposite leaves

The vast majority of mint family plants have opposite leaves along their stems. This means leaves that emerge in pairs right across from each other. They are also decussate opposite leaves, meaning that each new pair is rotated 90 degrees from the pair below it.

Note: Opposite leaves are usually distinguished from alternate leaves, where leaves alternate up the stem instead of being across from one another.

Two-lipped (bilabiate) flowers

Mint family flowers tend to have 5 petals that are fused together along most of their lengths. This gives the flowers the look of a tube with lobes around the tip. The fused petals are said to look like an upper and lower lip. The technical term for this is bilabiate. This is a common flower design among plants. Dozens of other plant families also have bilabiate flowers.

One benefit of this flower structure (for plants, anyway) is to prevent bees from collecting too much pollen. Social bees, such as bumblebees and honeybees, sometimes collect so much pollen that there’s nothing left for pollination. To protect against this, bilabiate flowers deposit pollen on the top of the bee, away from its pollen-gathering legs (nototribic flowers).

Mint family flowers tend to be arranged on sometimes stunning vertical spikes. Flowers form in clustered rings at points all along the stem. These are actually 2 separate clusters opposite one another (verticillaster). This is easiest to see on a species like Monarda punctata (spotted bee balm), where the cluster pairs are separated from other cluster pairs along the stem.

Fruits

Flowers turn into little containers with 4 nutlets, or small, dry fruits with a single seed inside. As always, there are exceptions. American beautyberry produces clusters of single-seeded purple fruits (technically drupes).

Wildlife value

As pollinator plants

Many plants in Lamiaceae are excellent pollinator plants. It’s almost a cliché to say, “bees love them,” but in this case, it’s true. They bloom for a long time, have fairly high sugar concentration in their nectar, and have strong scents to make it easier for bees to find them. Bees have good senses of smell.

Some species of bee specialize or strongly prefer plants in this family. These include some types of mason bees (Osmia spp.) and wool carder bees (Anthidium spp.).

Many species in the genus Salvia have evolved to be pollinated by hummingbirds. They have features like red or orange flowers shaped like tubes that don’t have a strong smell. (Unlike bees, birds navigate by sight and not smell.) They also don’t have “landing platforms,” which pollinators that hover don’t need.

Butterflies and moths also get nectar from Lamiaceae. Perhaps the most stunning are the hummingbird clearwing moths (Hemaris), which seem to especially like bee balm. These get their name from the way they hover like hummingbirds. Pictures don’t do them justice.

For shelter and food

The tradeoff for Lamiaceae being such excellent pollinator plants is that they provide less food and shelter than other types of plants. This is mainly because their essential oils deter plant eaters, and larvae usually need to be able to eat the leaves of the plants they hatch on.

However, some tiger moths in the Haploa genus feed on mints. Other moths that depend on plants in this family include the hermit sphinx (Lintneria eremitus), the orange mint moth (Pyrausta orphisalis), and the raspberry pyrausta (Pyrausta signatalis).
A few generalist moths will also lay eggs on Lamiaceae.

Songbirds like juncos, goldfinches, and sparrows eat the nutlets. They’ll also use Lamiaceae shrubs such as rosemary and lavender for nesting and cover.

Value to humans

This family includes many of the herbs we cook with, including basil, mint, oregano, thyme, rosemary, sage, marjoram, and savory. Their essential oils are released when exposed to heat (i.e. cooking).

The oils are also widely used in medicines and fragrances.

Many Lamiaceae are popular pollinator garden plants, such as anise hyssop (Agastache foeniculum), bee balm, and lavender. Another, clustered mountain mint (Pycnanthemum muticum) was named 2025 Plant of the Year by the Perennial Plant Association.

Read more

• A Wandering Botanist: Plant Family: The Lamiaceae, the Mints

• Floral Construction and Pollination Biology in the Lamiaceae - PMC

• Bilabiate Flowers: The Ultimate Response to Bees? - PMC

• Lamiaceae | PlantZAfrica

• Bee Balm, Scarlet, Monarda didyma | Leaves for Wildlife

• Family Profile: Lamiaceae - Florida Wildflower Foundation

• Lamiaceae - Wikipedia

• Hummingbird moth, Hemaris thysbe

• Osmia species (Hymenoptera, Megachilidae) from the southeastern United States with modified facial hairs:taxonomy, host plants, and conservation status

• ANTHIDIUM - Wool-carder bees

Eastern teaberry behaves like a colony-forming groundcover. It’s technically a shrub because its stems are woody. However, it only gets a few inches tall. It’s evergreen, with leathery leaves that are glossy and dark green.

It blooms in summer (July through August, though it varies depending on location). It has little whitish pink flowers that hang down bell-like from the point where each leaf meets the stem (the axil). Stems can support up to five flowers.

The flowers look like blueberry flowers. Blueberry and eastern teaberry are in the same plant family, Ericaceae. A small cluster of white leaf-like petals (sepals) protects the base of the flower.

The fruit are small red berries that may stick around through winter and into the next spring if nothing eats them. They’re actually a false fruit. The true fruit is a small capsule that grows inside the berry. The outer layer is formed from the sepals, which together are called the calyx.

If you crush a leaf, it smells like wintergreen.

How it spreads and grows

Eastern teaberry spreads through its roots (rhizomatously) and forms a mat. Each plant may spread about a foot. It grows slowly and lives for a few years.

It can also spread through seed, such as when birds eat seeds and disperse them somewhere else.

If you grow them in your garden, you can divide them in spring.

Wintergreen oil

Eastern teaberry produces an essential oil called wintergreen oil, mostly in its leaves, as a form of protection. It makes the oil when the leaves are damaged, such as when an insect chomps on it. (It’s also been useful for people in making medicines, though obviously that’s not why the plant evolved it.)

Natural habitat

Like blueberries, Eastern teaberry likes the organic matter, acidic soils, and shade of conifer forests. You’ll find it growing with oak, pine, hemlock, and spruce.

This is not a plant that likes disturbed areas, or areas affected by things like natural disaster, construction, or agriculture. One paper found that it only grew in places that hadn’t been ploughed historically.

Where it’s native

Native across a huge swath of north and east North America. Range listing is typically from Manitoba to Newfoundland down through Georgia and Alabama. Some sources list it as native to Minnesota, but most of the U.S. presence is further east, from Ohio through the eastern seaboard.

Wildlife associations

Pollinated by bumblebees and native bees. Flowers need to be buzz pollinated, a technique where the bee vibrates rapidly to release pollen. Or as one source put it, “they hold on to the corolla with their legs and shake it.”

Not all bees can do this—honeybees, for example, don’t buzz pollinate.

Several species of moths have been documented feeding on Eastern Teaberry, along with aphids and thrips. At least one moth, Cameraria gaultheriella, uses it to lay eggs.

Its berries aren’t eaten in huge amounts by any species, but they’re available in winter, when other food is scarce. In the wild, mammals that eat it include turkeys, grouse, northern bobwhite, pheasant, bear, mice, and foxes. Deer will eat the leaves and twigs, especially in winter.

Uses by people

Native people used Eastern teaberry for tea, treating kidney disorders, and as poultice for muscle and arthritis pain.

Teaberry extract is used to flavor tea, candy, gum, and medicine.

Sources this is based on

• Wintergreen | Gaultheria procumbens

• Gaultheria procumbens (Wintergreen): Minnesota Wildflowers

• Phytochemistry and Biological Profile of Gaultheria procumbens L. and Wintergreen Essential Oil

• Some observations on the reproductive biology of gaultheria procumbens (Ericaceae)

• Land-use history and demography of wintergreen

• Gaultheria procumbens (Eastern teaberry) | Native Plants of North America

• Checkerberry (Gaultheria procumbens) Growing & Care Guide for Gardeners

• Gaultheria procumbens | North Carolina Extension Gardener Plant Toolbox

• Gaultheria procumbens | PFAF Plant Database

• Cameraria gaultheriella (moth) - Wikipedia

And because that’s really the only thing you can do, it’s very easy to do it too much. Then their little leaves start to curl downward and turn yellow, which might make one think one needs to do something. And since the main thing you can do is water them…

You get the idea. I can’t prove this, but I bet overwatering is the greatest cause of indoor seedling demise among vegetable gardeners. Not that I’ve ever done it. Or had to relearn my lesson almost every year. Definitely not.

Here’s why it’s so easy to overwater indoor vegetable starts.

Roots need water and oxygen

Most people know plants need water. They use water in photosynthesis, transporting nutrients, and other critical things.

But they also need oxygen. They use oxygen to release energy they’ve stored. The result of this use is carbon dioxide, which they release back into the atmosphere. Plant scientists call this exchange of oxygen for carbon dioxide gas exchange.

Every part of a plant needs to take in oxygen and release carbon dioxide. Plants don’t have circulatory systems, so they can’t move oxygen around to parts of the plant that aren’t finding it. (Well, some plants like rice have ways to do this, but not the vegetable seedlings you and I are starting.)

Gas exchange isn’t usually an issue for the aboveground parts of a plant, but seedling roots are buried in whatever growing mix you’re using. They need to find oxygen and release carbon dioxide in the little spaces between the particles. These spaces are called pores.

When you water your seedlings, these pores fill up with water. Water-filled pores block oxygen from getting in and carbon dioxide from getting out. The water has to drain for gas exchange to start again. This is very bad for seedlings. They can’t get enough oxygen, or they’re being poisoned by too much carbon dioxide, or both. Either of these stops roots from doing what they need to do, which is things like sending water to other parts of the plant. It might also contribute to rot and various other issues.

Drainage lets plants breathe

When water drains out of your growing medium, the pores fill with air and roots can “breathe” again. So one of the things we can do to make sure roots get oxygen is give seedling containers (or blocks or whatever) time to drain. This might take more time than you think if you just look at the top of the soil.

One obvious way to allow drainage is make sure your containers have drainage holes in the first place. But that’s not the whole story.

Different pore sizes drain at different rates (or not at all)

Not all pores are the same size in your growing medium. They’re a range of sizes from large to very, very small.

The large pores drain quickly because of gravity. But smaller pores drain more slowly. And in very small pores, the water might not drain at all!

This is because of something called capillary action. In really small spaces, the forces that encourage water to stick to the sides of particles are stronger than the gravitational force pulling them down. You have also seen this if you’ve ever watched water “climb” a paper towel.

This is why most seed starting mixes use Spaghum peat moss or coco coir as bases. These materials have a variety of pore sizes and drain well. These both have sustainability issues, but they do provide physical qualities that help prevent overwatering.

Absorbed water is different than capillary water

There’s a difference between water that’s absorbed by a medium instead of being held in its pores. The absorbed water doesn’t take up pore space. It’s inside the physical material and releases slowly as pores empty out. Media that absorb water rather than just holding it allow roots to get both oxygen and water.

Water drains differently in your seed starting setup than outside

Another major contributor to overwatering is the size of seed starting containers.

Most people I know start seeds in cell trays or those tiny peat pots they sell at hardware stores. These are very small and short.

For mysterious physics reasons, in small containers, capillary action has an easier time winning out over gravity. (This has something to do with how much pressure is pushing down on the water in a shallow container.) This means that a pore that might eventually drain outdoors doesn’t drain in your little seed starting pot. It sits there full of water and doesn’t make room for air.

In addition, you’ll usually have a zone at the bottom of your container that’s saturated with water. (Some people call this a perched water table.) The water sticks to your growing mix. Surface tension and capillary action cause it to stick to the mix instead of turning into droplets and draining out. This could be an issue in very small containers, since the roots won’t have much room before they hit this saturated area.

As we already discussed, you don’t want roots sitting in water. This could cause them to suffocate or rot.

Kitchen sponge experiment

You can actually model the perched water table with a kitchen sponge. Soak it with water and hold it horizontally. Water will drip out but eventually stop. Now turn it vertically. After a moment, water will start dripping again. More height equals more drainage. This is the mysterious physics that causes water to stick around in short containers.

Soil blocks

My experience has been that soil blocks behave pretty differently than the starter cells. Because they’re open, they tend to dry out much more quickly. So if you’re using soil blocks, some of the small container issues might not apply.

A few other drainage disadvantages your indoor mix has

In addition to being in a smaller container, your seed starting mix doesn’t have earthworms and insects burrowing about, creating pathways for water and air. There’s also less wind and sun indoors to help evaporate excess water.

For these reasons plus the small container issue, growing mixes that might be fine in a raised bed or a large container provide poor drainage in seed starting setups. Potting soils and composts, for example, may retain too much water. You’d need to mix them with something that provides drainage, like rice hulls or sand.

What all this means for seed starting

Your indoor seed starting environment is very different than your outdoor garden. this means we need to approach watering differently.

First, let seedlings dry out between waterings, maybe more than you think you need to. (Obviously you don’t want to let your seedlings desiccate, but I personally tend to not let them dry out enough.)

Even if the top of the seed starting mix is dry, make sure the bottom isn’t still damp. You might have to check this by burrowing down a little with your finger or learning how heavy something is when it’s watered vs. when it’s dry.

And finally, choose or make a mix that drains well. If a mix seems damp long after you watered, it’s probably not good for seedlings. We need a cycle of wet and drained to make sure little roots are getting both water and air.

It’s difficult to not do the one thing we can do with vegetable seedlings. But if we want them to make it to transport time, it’s important that we leaf (sorry) them alone with the watering can a little more often.

Sources this is based on

More on this topic

• “Containers.” Chapter 7 of Tropical Nursery Plants (2014)

• Nursery manual for native plants: A guide for tribal nurseries - Volume 1: Nursery management

• How Plants Breathe and Exchange Gases | RHS Advice

• Basics of Plant Respiration

Virginia strawberry is a low-growing groundcover. It appears to have leaves arranged in groups of 3, each with toothed edges. Each of these is technically a leaflet, part of a single compound leaf. Each leaf also has a stem, or petiole that attaches is to the crown of the plant (the place where the aboveground parts meet the soil). These compound leaves are usually around 4 inches tall, give or take a couple inches.

Virginia strawberry flowers in spring, usually in April or March, depending on where it’s located, and continues throughout the season. Flowers are white and small, about half an inch across. They have 5 petals and a yellow center. There are multiple flowers per flower stalk, usually around five, though there can also be many more. Flower stalks are usually a little taller than the leaves.

The fruit ripens in late spring or early summer. It’s red and much smaller than what you’d buy in a grocery store. I personally think it is sweeter, more like candy.

One other feature of the plant is its runners, or stolons. These might look like low-lying stems, especially since you can sometimes see leaflets forming on them. They’re usually red and hairy. They also help Virginia strawberry spread.

How it spreads and grows

Virginia strawberry mostly spreads through its stolons. People sometimes call these “runners.” The stolons have joints, called nodes, that can make roots when they touch the soil. (These are a type of adventitious root, or root that’s made from non-root tissue, usually for some specific reason. For example, some vines make adventitious roots to help them climb.)

These roots grow down into the soil and form the foundation of a new plant. The mother plant transfers energy and nutrients to help these new plants develop. This is a form of vegetative reproduction.

Each stolon can make multiple new plants at different nodes along its length. In addition, each plant can produce multiple stolons. This allows Virginia strawberry to spread quickly and form colonies. Some gardens even use it as a lawn. Someone I spoke with at the Garden in the Woods in Massachusetts told me, “It’s tough enough that you can walk on it, but you can’t play soccer on it.”

Virginia strawberry also reproduces through seed, though this is secondary to vegetative reproduction. Birds and mammals eat the fruits and later disperse the seeds (i.e. they poop them out somewhere else—and with a little bit of fertilizer).

Natural habitat

This plant grows in many different conditions, including prairies and meadows, the edges of forests, and openings in woodland canopies.

In the woods, it will grow up through dense leaf duff in spring.

It’s an adaptable plant. My neighbor has some volunteering in a lawn in full, south-facing sun, and I have some growing under the dappled light of black cherry trees.

If you want to grow it, find somewhere that gets at least some light and isn’t too wet.

Where it’s native

Fragaria virginiana is native across a huge swath of North America, including almost all of Canada and the United States. Most native range maps show most or all of the United States and Canada (except for on islands like Hawaii or Puerto Rico).

Check a range map.

Wildlife associations

This is an incredibly important native plant for wildlife. It supports a huge number of butterfly and moth caterpillars as a host plant. (Some sources suggest more than 70!) These in turn are a critical source of nutrients for songbirds raising their offspring, among other wildlife.

The most often-cited caterpillar is the gray hairstreak, probably because it’s pretty. However, the gray hairstreak is a generalist. It feeds on lots of plants. Moths that are more dependent on this plant include smeared dagger moth (Acronicta oblinita), the purple-lined sallow (Pyrrhia exprimens) the strawberry leafroller (Ancylis comptana).

A huge range of birds and mammals eat the fruits, including robins, cedar waxwings, wild turkeys, voles, box turtles, and bears. (Also the usual suspects for your suburban garden, such as deer, mice, and squirrels.)

The flowers provide pollen and nectar for a large range of insects, too. These include native bees (bumblebees, mason bees, sweat bees) and generalist pollinators, beetles, and hover flies.

Uses by people

Like wildlife, people have used–and still use–this plant extensively. Various Native American tribes ate it, dried the fruit for winter, and used the leaves as part of a medicinal tea for digestive problems. Early colonists also ate it and used it for preserves.

Fragaria virginiana is also the parent species of one modern cultivar, Fragaria × ananassa. It was crossed with a Chilean strawberry (Fragaria chiloensis) in the 18th century.

Today, people continue to forage for it. They also add it to native plant gardens as a groundcover. Its ecological value makes it excellent for restoration projects.

Sources this is based on

• Fragaria virginiana | Native Plant Trust

• Fragaria virginiana (Virginia strawberry) | Native Plants of North America

• Fragaria virginiana | USDA PLANTS database

• Wild Strawberry | Maine Native Plants

• Wild Strawberry, Fragaria virginiana | Virginia Native Plant Society

• Science of Plants — Shoots | University of Minnesota

• Virginia Strawberry (Fragaria virginiana) | bplant.org

Purple coneflowers grow 2-5 feet tall in clumps that can be 1-2 feet wide. They start blooming in spring or early summer and can keep going until nearly fall. A single plant can produce dozens of blooms per year. In your garden, if you deadhead them, they might bloom well into fall.

They have large flowerheads that are about 3-5 inches across. At the center is a spiky dome, which starts out yellowy brown and matures in fall to orangey brown. The “spikes” in this dome are called disk florets. These produce seeds and provide nectar for pollinators.

Around the outside of the dome are what look like petals. These are ray florets. (Technically, each ray floret is a flower. Petals are individual structures on a flower.) The job of a ray floret is to be colorful and attract pollinators.

On purple coneflower, the ray florets range from pink to a light magenta color. They tend to angle down (they’re reflexed), sometimes quite a lot. I couldn’t find a source that says why, but it’s very common.

The leaves and stems are both hairy. The leaves are rough and dark green. Along the stem, leaves are narrower and lance-shaped. Leaves at the base of the plant (basal foliage) are longer and much wider.

In winter, the seed heads remain upright. They’re spherical and brown. When it snows, they have a lovely frosted appearance.

How it spreads and grows

Loves full sun, though it will put up with a little shade.

Only lives a couple years but will reseed itself. The seed heads remain on the plant through fall and winter, gradually dropping when they’re ready. New plants will then sprout near the mother plant, over time forming a larger colony. This happens fairly slowly in the garden compared with more aggressive plants, such as bee balm or mountain mint.

Each plant’s “clump” gets wider over time, up to about 2 feet.

Birds love to eat the seeds in winter, and that’s one reason people grow purple coneflower. However, they fully digest the seeds. They don’t spread them.

Unlike most Echinacea species, purple coneflower does not have a huge taproot. Instead, it has a shorter, shallower root system. It expands outward as it grows (that is, the “clump” it grows in gets bigger”).

The root system also helps it put up with more moisture than other Echinacea species—perhaps this is one reason it’ll grow along water ways.

In your garden

If you’re growing it in your in the garden, make sure it gets plenty of sun and isn’t in extremely wet soil. (It certainly seems to thrive in lots of different garden soils!) You can also propagate purple coneflower by dividing its root crowns.

If you grow it from seed, this plant might not bloom until the second year.

This is a popular garden plant, and there are a lot of varieties (in addition to the “straight species”). At least 2 places have done trials to evaluate how different varieties of purple coneflower “perform” (for example, attract the most pollinators).

• Chicago Botanic Garden Comparison of Echinacea cultivars

• Mt. Cuba Center Echinacea trials

Natural habitat

Grows in prairies and openings in wooded regions with dry, sunny conditions. Also grows along waterways. One of the things that makes it different from other Echinacea species is that it tolerates wetter soil.)

Where it’s native

Most sources agree that purple coneflower is native to the southeastern and mid-Atlantic regions of the U.S. This includes Alabama to eastern Texas and north to Illinois, Ohio, and Indiana. Other sources suggest a larger range, stretching north through Maine and into Canada.

Check a range map.

Wildlife associations

Valuable pollinator for bees, especially bumblebees and lots of native bees such as long-horned bees (Melissodes). Also attracts butterflies and occasionally hummingbirds.

Many types of bee also use purple coneflower to survive winter. They nest in its dead, hollow stems. These include leafcutter bees, mason bees, and carpenter bees. This is one reason to not cut the stems back–or at least not to cut them back too far–in the fall.

Purple coneflower is a host plant for a few types of moth, including the silvery checkerspot butterfly (Chlosyne nycteis) and Wavylined Emerald moth (Synchlora aerata).

Many birds eat the seeds, especially in winter. These include American goldfinches and chickadees. This is another good reason to leave the stems standing in the fall!

Uses by people

Plains peoples (among many) such as the Lakota, Cheyenne, and Kiowa used purple coneflower medicinally. Early settlers used the roots to treat many types of sickness, too. They also used it to treat animals.

This is one of 3 Echinacea species used today as an herbal remedy and in teas. (The others are pale purple coneflower [Echinacea pallida] and narrow-leaved coneflower [Echinacea angustifolia]).

Sources this is based on

• Eastern Purple coneflower, Echinacea purpurea (L.) Moench

• Eastern purple coneflower | USDA Plant Guide

• Echinacea (Coneflower) morphology is different than you may imagine | Annotations

• Physiological Mechanisms of Drought Resistance in Four Native Ornamental Perennials in: Journal of the American Society for Horticultural Science Volume 119: Issue 2 | ASHS

• Capitulum, Disk, Disk Floret, Floret, Ligule, Ray Floret

• A Comparative Evaluation of Echinacea Cultivars | Chicago Botanic Garden

• Chicago Botanic Garden Comparison of Echinacea cultivars

• Mt. Cuba Center Echinacea trials

• Echinacea purpurea (L.) Moench: Biological and Pharmacological Properties. A Review | MDPI