Will the real native plant please stand up?
As more and more gardeners learn about the benefits of native plants and incorporate them into their landscape designs, experts have a few words of caution that boil down to “caveat emptor,” or buyer beware.
There are natives, which are the wildflowers that sprung up and adapted to a specific region with no human involvement, and then there are plants known as “nativars.” And yes, the difference of a couple of letters matters.
Going back to roughly the 1600s, scientists have a remarkably good track record of which plants were original to North America versus which were intentionally introduced and which accidentally escaped, according to Greg Spyreas, a botanist with the Illinois Natural History Survey.
Lists of natives are readily available but it’s important to make note of a plant’s scientific Latin name, not just its common appellation, said Spyreas.
To use one of the area’s common natives as an example, a Chicago gardener should look for plants labeled Monarda fistulosa, not just “bee balm.”
Seems straightforward enough, but nativars muddy the waters. They’ll have the same scientific name, with an added descriptor, like Monarda fistulosa ”blue brilliance.” (Not an actual plant name.)
While the native and nativar are closely related, that descriptor can have significant implications and, in some cases, defeat the purpose of choosing a native in the first place.
A nativar is a native that’s been genetically tweaked in any number of ways. It may have been engineered to bloom longer, resist certain diseases or reach a lesser height. The selected trait is almost without exception more desirable solely from a gardener’s standpoint, either in terms of aesthetics or reliability.
What’s good for a gardener, though, may not be great for wildlife.
There are a myriad of reasons botanists have promoted natives — they hold topsoil in place, are better at absorbing stormwater and are drought tolerant, to name a few — but the primary purpose, Spyreas said, is that they’re a boon to wildlife.
“Every single group of animals on earth are showing just massive, fast declines in their population sizes, many of them going extinct, for all the reasons that we know. There’s more urbanization, there’s more agricultural land, we have invasive species choking them out, climate change, there’s poaching,” he said. “So, if we can use some of our urban gardening habitats to promote and encourage wildlife, we’re doing a really, really good thing.”
That’s because a region’s wildlife coevolved along with its native plants, and they rely on the natives for food and habitat. Perhaps the best-known example is the monarch butterfly, whose caterpillars only eat milkweed plants (Asclepias spp). No milkweed, no monarchs.
Swapping in a nativar for a native isn’t an equal trade, at least not from wildlife’s standpoint. “Generally, you get a little bit to a lot less (ecological) benefit from a nativar,” said Spyreas.
The best-case scenario would be something like a coneflower (Echinacea spp) nativar, selected simply to be shorter than a native echinacea. (In the U.S., there are nine native species of echinacea.)
“If you don’t really like the tall one that flops over sometimes, you want just the shorter one, that is going to provide the exact same wildlife benefits as the native because it’ll have all the pollinators going to the flowers and it’ll have all the caterpillars eating it,” Spyreas said.
Other seemingly minor variations can be more problematic.
One study showed that altering the leaf color of a native plant — changing it from, say, the native’s green to the nativar’s purple — resulted in a three- to five-fold reduction in feeding preference by insects when it came to the nativar.
Among the most egregious deviations between natives and nativars has been the trend toward “double-flowered” plants, which have multiple layers of petals, Spyreas said.
“When you start to get some of the crazy selection for some of the flowers, whether it be a double or maybe some selections for some really different colors, essentially the flower becomes more and more about the petals and weird colors and less and less about being a reproductive organ,” he said. “So, you’re not producing the nectar, you’re not producing the scent that’s attracting the pollinator, you’re not producing seeds that animals like to eat. The further that flower gets away from its native look or feel or whatever, that’s where you start to lose a lot of those pollinator benefits.”
There are no hard-and-fast rules about what traits will impact a nativar’s effectiveness when compared with a native. But a general tip-off: “If you know what the native flower looks like, and you say, ‘Whoa, that’s crazy different,’” that nativar should be avoided, Spyreas said.
Before heading to the garden center or nursery, do a bit of research, write down scientific names and then scrutinize labels before making a purchase.
“You’re going to get the most bang for your buck by planting the straight native,” Spyreas said.
“Most bang,” it should be clarified, for wildlife.
Natives are not for everyone, Spyreas said. They can be finicky, thriving only in a super-specific habitat. They can be unwieldy, spreading with abandon like the weeds for which they’re often mistaken. And they can require more care than the term “wildflowers” would suggest.
“The rabid native gardeners know their conditions and they know their plants,” he said. That knowledge is often gained through trial and error.
“Let’s be honest, some natives are just fussy,” said Spyreas. “But once you get the right plant in the right spot, you’re really in business.”