The Trouble With Milkweed

“We have to convince the nursery industry that native plants are about more than just looks.” — Doug Tallamy

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Lately, I’ve been diving into seed and plant nursery catalogs. Making elaborate lists. Planning new pollinator gardens. Is there a better way to spend these rainy April days? Other than going for a hike, of course!

Wild leeks (Allium tricoccum), The Morton Arboretum, Lisle, IL.

As I thumb through the catalogs, planning to plant more prairie at home, I’m amazed at the number of “native” plants now on offer. Natives are hot, hot, hot! I wonder if the push for us to support monarch butterflies, native bees, and other pollinators may be having a positive influence.

Common milkweed (Asclepias syriaca), Schulenberg Prairie, 2016.

As I flip the catalog pages, I take a closer look. Wait a minute. I know this plant—the wonderful Butterfly Weed (Asclepias tuberosa), a favorite of mine in my backyard prairie patch and a magnet for monarch butterflies and monarch caterpillars. But what is ‘Hello Yellow’ Milkweed? Hmmm… . Not the orange version I see on the prairies in the summer.

Monarch butterfly (Danaus plexippus) on Butterfly Weed (Asclepias tuberosa), Schulenberg Prairie, Lisle, IL (2014).

Asclepias incarnata, Swamp Milkweed, is another favorite of mine. It loves the wet spots in my backyard prairie planting and attracts plenty of monarchs. I page through another nursery catalog and there it is. Or…is it? The scientific name is the same. But it’s called ‘Soulmate’ Butterfly Flower. And here it is again…yet another catalog lists the same scientific name, but the milkweed is white and called Swamp Milkweed ‘Milkmaid.’ Is this the same plant I see on my prairie hikes?

Swamp milkweed (Asclepias incarnata), Schulenberg Prairie, Lisle, IL. (2020)

Are these native milkweeds? Do I want them in my garden?

Whorled milkweed (Asclepias verticillata), Crosby’s backyard, Glen Ellyn, IL (2021).

What’s in a name, anyway? As it turns out…a lot.

Many cultivars—sometimes called nativars— are popping up in garden catalogs, right alongside the native plants (or even touted as natives). It’s confusing isn’t it?

Purple milkweed (Asclepias purpurascens), Schulenberg Prairie, Lisle, IL (2017).

Time to begin searching for more information.

Wild bergamot (Monarda fistulosa), Schulenberg Prairie, Lisle, IL.

Some of these “native” plants in the catalogs are cultivars, or sometimes called nativars. Cultivars are—simply put—a species that has been selected for certain traits, such as a particular color, and then bred to ensure the subsequent plants of that species exhibit those traits. On the positive side, many native plant cultivars have increased vigor. That’s good, right? As a gardener, I like that in a plant. But does it perform in the same way, if it finds its way to our natural areas?

Schulenberg Prairie, Lisle, IL.

I’m not sure we know. Yet.

Butterfly Weed (Asclepias tuberosa), Belmont Prairie, Downers Grove, IL (2020).

How can you spot a native that’s a cultivar or nativar? A good clue here is a fancy name, vibrant color, a doubled flower, or a larger-than-normal size. Look for a cute name in quote marks (i.e., Echinacea purpurea ‘Purple Passion’). These native cultivars may appeal to gardeners who want more jazzy blooms than the native itself might offer. Echinacea —coneflowers—often get this treatment. Evidently milkweeds are getting it too. And why, I wonder, when the native itself is so pretty?

Regal fritillary butterfly (Speyeria idalia) on pale purple coneflower (Echinacea pallida), Nachusa Grasslands, Franklin Grove, IL.

I continue looking for information, and learn multiple sources recommend avoiding double-flowered native plant offerings, as they can be tough for pollinators to gain access to pollen and nectar. Some cultivars of particular species may not set seeds. As seeds are valuable for wildlife, this seems like a missed opportunity.

Butterfly Weed (Asclepias tuberosa), Crosby’s backyard, Glen Ellyn, IL (2020).

I also learn that cultivars that have purple or red leaves may be tougher for caterpillars to feed on. The National Wildlife Federation also notes, “Presumably, the more variegation (in foliage), the less nutritious the plants are for wildlife.” Does this mean none of my plants should have variegated foliage or have purple leaves? Of course not. But learning about these plant features reminds me to be intentional when I plant. My desire for these attractive features would need to be balanced by including other wildlife-friendly plants. And in my small yard, how much room do I want to give to plants that aren’t pollinator or wildlife-friendly?

Butterfly Weed (Asclepias tuberosa), Schulenberg Prairie, Lisle, IL (2020).

I found this article compelling from the National Wildlife Federation: “Native, or Not So Much?” It includes a wonderful interview with Doug Tallamy, author of Bringing Nature Home, and helped me clarify my thinking as I prepared my catalog order.

Whorled milkweed (Asclepias verticillata), Nachusa Grasslands, Franklin Grove, IL.

I also appreciated this article: The Nativar Conundrum. It reminded me that cultivars can offer us disease resistance and bigger fruits in garden plants, like trees and shrubs. There are benefits! But there is so much we still have to learn about native prairie plants and cultivars. For now, with my prairie natives, I will choose the originals first. Until we know more, I’d rather stay with the tried and true. I’m not ready to trade in the original species. I’ll like to know more about the impact of the fancier cultivars on pollinators—and our prairie communities.

Swamp milkweed (Asclepias incarnata) with cardinal flower (Lobelia cardinalis), Nomia Meadows Farm, Franklin Grove, IL.

Which brings us back to the milkweeds. While deciding what milkweeds to plant this season, I learned all milkweeds are not necessarily beneficial to monarchs when planted in my state. Tropical milkweed (Asclepias curassavica) is a great example, as it is not native to the United States, and has been noted as detrimental to monarch butterflies when planted in the Midwest. Monarchs love tropical milkweed—and their caterpillars seemingly flourish on it. When I read this article from Xerces Society, I learned the damage this beautiful milkweed may cause the monarch population, including breeding confusion, potential toxicity to caterpillars as our climate changes, and migration interference. Who wants to be a part of that?

Whorled milkweed (Asclepias verticillata), Crosby’s backyard, Glen Ellyn, IL.

Back to the catalogs. There are so many tempting “natives” to consider buying! But–because I receive a lot of catalogs from all over the United States, many of the “natives” they list aren’t native to the place where I live. Yes, even some milkweeds! If I’m not sure about a plant, a good source for determining if a plant is native to my area is to use the USDA website. I’m also leery of the “prairie mixes” touted by various catalogs. So many of the species aren’t native to my region. Better to buy the species I know.

Are all my garden plants native? No! I have a mix of about 70 percent natives in my garden and 30 percent traditional garden plants. I doubt I could part with my zinnias!

Monarch butterfly (Danaus plexippus) and ruby-throated hummingbird (Archilochus colubris) on Cut-and-Come-Again Zinnias (Zinnia elegans), Crosby’s backyard, Glen Ellyn, IL.

But I want to continue increasing my native plant percentages. And I want to know what I’m buying—is it the “true native” or a cultivar?—and make my decisions thoughtfully and intentionally. Every plant I grow needs to earn its place in the garden. I’m still learning about native cultivars, and as more studies are done, I’ll keep an open mind. The trouble right now is we just don’t have enough information.

Common milkweed (Asclepias syriaca), Schulenberg Prairie, Lisle, IL (2019).

With milkweeds, I’m finding the decision this spring is easy. In Illinois, there are more than 20 species of milkweed native to our state. A good list of milkweeds found in the Chicago region is listed here from Wild Ones. Or click here for the list of milkweeds found in Illinois, and to see images of these beautiful monarch magnets.

Butterfly Weed (Asclepias tuberosa), Schulenberg Prairie, Lisle, IL (2021).

Seeing these lists makes my milkweed buying decision easy this spring. No trouble at all. With so many beautiful native milkweeds available to me, why settle for less than the real thing?

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The opening quote is from Janet Marinelli’s National Wildlife Federation interview with Doug Tallamy, which can be found at Native, or Not So Much? All of us who love the prairie need to keep learning and keep an open mind as new developments occur in the native plant arena, and work toward a healthier, more diverse natural world that benefits all creatures. Tallamy’s books are excellent reads, including Bringing Nature Home and The Nature of Oaks. Thanks also to Lonnie Morris of DuPage Monarchs, who brought the tropical milkweed issue to my attention.

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Join Cindy for a class or program in April! (Visit http://www.cindycrosby.com for more).

Tuesday, April 12, 7-8:30 p.m. The Tallgrass Prairie: Grocery Store, Apothecary, and Love Charm Shop at Glenview Public Library, Glenview, IL. Open to the public (in person). Click here for details.

Wednesday, April 13, 7-8 p.m. Add a Little Prairie to Your Garden for Glencoe Public Library and Friends of the Green Bay Trail. Online only, and open to the public. Register here.

April 25, 9:30-11am The Tallgrass Prairie: Grocery Store, Apothecary, and Love Charm Shop with Country Home and Garden Club, Barrington, IL (In person). Closed event. For more information on the garden club click here.

Join Cindy for one, two, or three Spring Wildflower Walks at The Morton Arboretum! Learn some of the stories behind these spring flowers. April 22 (woodland, sold out), April 28 (woodland) and May 6 (prairie, one spot open) (9-11 a.m.). In person. Register here.