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Natives: The Rest of the Story

The genie’s out of the bottle when it comes to non-native plants. Here’s why that’s not such a bad thing.

Beginning gardeners concerned about the environment often assume that planting nothing but native plants is the only way to go. I’ve irked a few experienced gardeners—and more than a few environmentalists—over the years by questioning that assumption. Might as well stay the course. Is planting nothing but natives akin to driving a Prius?

Not in my garden.

Staunch nativists are quick to point out that “exotics,” as non-natives are called, are difficult to grow. They’re right—some exotics are terrifically ill tempered. For example, high-altitude alpines are typically ground-hugging plants with tiny leaves and brilliant flowers—features that make survival possible in bitterly cold, windy, and barren conditions like the peaks of Colorado. Try growing them in the tropics, and they will teach you a hard lesson about moving a plant from its natural habitat. Alpine lovers grow their small treasures in troughs with perfect drainage. Growing alpines is considered a challenge akin to bonsai. Why? For all that perfect drainage, the plants still die. Maybe they’re homesick.

These same staunch nativists also like to say that exotics are the imperialists of the plant world. Having just removed an 80-year-old buckthorn hedge from my yard—with the help of my husband and a superb pull saw—I entirely agree. European Buckthorn was brought to this country from Europe. It makes a marvelous hedge, with its dense branching habit and dark, oval-shaped leaves. It also produces small round berries that birds love to pluck from those branches with thoughts of putting food on the table back at the nest, only to drop them mistakenly in some drainage ditch, public forest, or neighbor’s garden, where the berry’s seed takes root and multiplies like a dandelion gone to seed (another exotic, by the way, originally imported from Europe).

It goes without saying that exotics can be extremely invasive. Because they aren’t native to these parts, they have no natural predators. (For the record, buckthorn isn’t invasive in its northern French home because, there, competitors and biology rein it in.) It’s easy for exotics to crowd out the original settlers in a pattern not unlike what happens when young professionals decide to gentrify a formerly poor neighborhood, jacking up the rent so high that only rich folks can afford to live there. Every invasive plant has its own method: some spread through the air, like buckthorn; others send out underground roots that become like tentacles and strangle other plants.

We all know by now that monocultures are not a good thing. Buckthorn, purple loosestrife, and other notorious invasives insist not only on moving in, but shoving neighbors not of their own kind out. When landscapes are overrun with invasive exotics, the native plants die and the balanced ecosystem that made the area healthy and beautiful is destroyed.

So, you might be asking, if I understand all this, why aren’t I tearing out my Japanese maple and filling the hole with common milkweed?

For one thing, even among nativists, the precise definition of native remains ... a bit unclear. Officially, natives are plants whose roots are long and deep in these parts. Plants that call Minnesota home. Or maybe the Upper Midwest. Or, possibly, Midwest? America? North America? The western hemisphere? You see the problem.

But even if you settle on the geographic boundaries, or just make a list of natives you like (bee balm, liatris, rudbeckia, and the like), things are still more complicated than they seem. Nativists like to think all natives are fun-loving and environment-saving, and all exotics are ecosystem destroyers. That’s far from true. Bee balm can be extremely invasive. Another native, the common milkweed, became such a thug in my garden I had to remove it. Rudbeckias, too, are rampant spreaders in my garden. I don’t hate them, but I do pull them out when they get too pushy.

Here’s my ultimate invasive native story: I bought an heirloom morning glory from Seed Savers Exchange years ago thinking ‘Grandpa Ott’, a deceptively dainty, purple-flowered vine, would be a nice change from the ubiquitous and sterile garden staple, ‘Heavenly Blue’. I love self-seeders, but enough is enough. Pulling up old man ‘Ott’s’ offspring by the bucket load every summer since I first planted it is now my most loathed garden chore. This supposedly endangered species will outlive our own—and take over the entire planet—if my garden is any indication.

On the other side, I know of many wonderful exotics that are excellent neighbors, but have had their reputations besmirched because of their racial differences. You know the drill. They don’t come from here. Be on guard.

Maybe I’m just nostalgic for the melting pot, but I wish we’d go back to thinking in terms of a plant’s personal characteristics instead of obsessing on place of origin. The steppes of Siberia are not unlike our Great Plains region. Does that mean the Russians shouldn’t plant our native coneflowers? Call me old and crotchety but I’m not going to tell people they can’t use all the crayons in the box to color their own plot of earth.

I do hope that people will spend time doing their plant homework. I’ve learned (often the hard way) that the more plants I grow, the better I understand how to create a happy plant family. But it’s never been a black and white issue.

I’ll leave you with just one last thought on the issue of natives versus exotics. Even if we could put the genie back in the bottle, and start over with a fresh slate of prairie ground, would we really want to? 

Bonnie Blodgett publishes The Garden Letter and is writing a book about smell.

A Feast of Natives and Exotics

Sometime around the end of August, Monarchs emerge from their pupae and begin to prepare themselves for a strenuous flight southward. These butterflies must store the fat that fuels their 3,000-mile-long journey. Here’s a list of natives and exotics that help them on their way.

» Natives

Swamp milkweed
Common milkweed
Butterfly weed
Purple coneflowers
Rough blazing stars
Meadow blazing stars
Black-eyed Susans
Cardinal flowers

» Exotics

Mexican sunflowers
Flowering tobacco
Petunias
Nasturtiums
Hollyhocks
Verbenas
Zinnias
Asters
Blanket flowers
Daylilies
Russell lupines
Peonies
Sedums
Canadian lilacs
Korean lilacs
Weigela

Prepared by Carrol Henderson, supervisor of the Nongame Wildlife Program at the Minnesota Department of Natural Resources.