Grow Native Plants to Help Pollinators, But Here's Why You Should Think Twice About Nativars
Some plant varieties are better than others at supporting butterflies and bees. Here's what you need to know.
In my garden, I often see chickadees, wrens, and cardinals flitting around. But lately, I've noticed that a lot of other wildlife I used to see has disappeared, especially pollinating insects. I've spotted only three butterflies so far this spring, and a handful of honeybees from a neighbor's hive, but my native bees are missing. And at night, fewer fireflies are flashing their yellow-green lights in the grass. Experts agree that growing native plants in your yard can help out pollinators and other beneficial wildlife. Plus, lots of these plants are beautiful. You also may come across "nativars" that offer variations in color, size, and other characteristics. But are they as good for pollinators, and should you plant them?
What Are Native Plants?
Native plants are species that grow naturally in a particular area or region. Over time, they've evolved to have a mutually beneficent relationship with native wildlife. Bees visit flowers with abundant nectar, for example, and transfer pollen as they visit other flowers. Because these plants are already adapted to your soil and weather conditions, they often are lower maintenance than plants from other parts of the country or the world.
What Are Cultivars?
Cultivars are what you'll most likely come across in garden centers, nurseries, and big box stores these days. New ones come out every year, and they often have fun, flashy names, such as 'Vanilla Strawberry' hydrangea, designed to grab your attention. Sometimes those names are even trademarked.
The word "cultivar" is actually a mash-up of "cultivated variety," which just means a named variation of a particular species that results from human efforts to create them. Cultivars offer characteristics that gardeners find desirable, such as bigger blooms, a more compact size, or better disease resistance.
What Are Nativars?
"Nativar" is a term coined by Allan Armitage, professor emeritus of horticulture at the University of Georgia, as a way to differentiate these plants from other cultivars. Most nativars are intentional crosses between wild, native plant species or between other nativars. Some occur naturally, adds Mary Phillips, who manages the National Wildlife Federation's Garden for Wildlife program.
Plant breeders began focusing on nativars as people became more aware of how essential native plants are to supporting declining pollinator populations, Armitage says. Yet, gardeners still wanted the same improved features that cultivars offer. "The demand was there, but many [native species] were not attractive enough for gardeners," he adds.
So, breeders got to work creating wildlife-friendly plants that were also more showy or easier to care for in gardens. For example, 'Desert Sunrise' is a more vigorous, colorful cross between two species of hummingbird mint that are native to the southwest. And Eastern native threadleaf coreopsis now comes in an array of varieties with different colored flowers and more compact stems such as popular 'Moonbeam'. While nativars are seldom labeled as such in garden centers and nurseries, tags that indicate a plant is butterfly- or pollinator-friendly are a clue.
Unfortunately, Armitage says, these nativars sometimes lose their pollinator benefits during the breeding process. This also can happen with regular cultivars. Though these varieties may have been improved from a gardener's perspective, the resulting plants may produce less nectar, for instance, or have double layers of petals that make it harder for butterflies and bees to get into them.
What Should I Plant for Pollinators?
Not everyone agrees that nativars help wildlife, says Phillips. If their pollinator benefits haven't been bred out, "nativars can provide some elements of nectar, shelter, and cover for wildlife." But overall, she thinks they have more cons than pros.
The problem, Phillips says, is that nativars and cultivars often can't support the full life cycle of some pollinators. "Generalist pollinators, like bumblebees and some butterflies, can go to a variety of plants for nectar," she explains. But others need specific plants, like the monarch caterpillars that eat only milkweed leaves. "Also, some nativars that are mass-produced and shipped may be treated with chemicals due to regulations about vegetative transport." She warns against using any chemicals in your garden, because they defeat the purpose of planting for wildlife.
On the other hand, Armitage cites a study from Mt. Cuba Center, a botanical garden in Delaware, where research has shown that many nativars lured just as many leaf-eating insects as pure natives. The exception was nativars with darker-colored foliage. Researchers concluded more study is needed before they can recommend which plants to grow, because natives, nativars, and cultivars can affect not only pollinators, but also whole ecosystems, the climate, and more.
Ideally, Phillips says, people should grow more pure natives in their landscapes. "If you're really trying to benefit the planet," she advises, "aim for planting 80% natives and 20% cultivars. Studies have shown that where diverse plants were installed (plants with good genetic diversity), butterfly and bee populations improved."
While research continues, experts seem to agree that native plants offer the most benefit for pollinators in terms of nectar, pollen, seeds, shelter, and nesting sites. Nativars and cultivars are further down the list. A handy tool on the NWF website lets you enter your zip code to find a list of the highest-performing plants for pollinators.
Don't worry that a garden filled with natives or nativars will look wild or messy. "Go for a wildflower-y, meadow look or garden look," Phillips suggests, with native trees and shrubs for structure. As an example, she says, "I put in oakleaf hydrangeas and a border of inkberries for an almost-English garden effect with boxwoods." She also suggests staggering the heights of your plants, and putting the bigger, more wild-looking ones at the back so your design looks purposeful.
Armitage says it's important not to sweat exactly what you plant too much, though. "Certain pollinators like certain plants, such as black swallowtail butterflies that like dill. But if you just want butterflies and bees and all those other cool things, use common sense. Just plant flowers. We're blessed to have so many native plants [all over the United States] that are ornamental."
Phillips echoes this thought, saying, "You have the amazing power to do something right where you live to support and help bring back the ecosystem and declining wildlife species."