When is a native plant not a native? There's no funny answer. This is not a riddle. It's a question that has many gardeners scratching their heads.
The dilemma is with cultivated varieties, or cultivars, of native plants. Nativars, in trade lingo. Or, as some people call them, near natives.
Nativars trace their beginning to native plants. But then, a plant breeder creates a new hybrid by deliberately crossing two related plants. Or someone notices a significant difference in one plant in a native plant population. Maybe the unusual plant blooms earlier than its siblings. Or maybe it's smaller, a better fit for small gardens. Maybe the flowers or foliage are a gorgeous new color. Perhaps the new plant is sterile, so it won't seed around promiscuously. Maybe its blossoms are double, for more flower power. And maybe its foliage is pest-resistant, so insects won't eat the foliage.
So, what's the problem?
For one, sterile plants produce no pollen or seeds for butterflies, bees and birds. Double flowers are more difficult for pollinators to penetrate. Foliage or flowers of unusual colors may not be recognized as a food source. Pest-resistant nativars, although seemingly a boon for the gardener, may not support caterpillars and other insects that are vital food sources for baby birds. And gradually, the gene pool shrinks.
On the other hand, many nativars offer positive attributes and support wildlife, too.
The flowers of Major Wheeler honeysuckle vine, for example, are just as attractive to hummingbirds as the species (Lonicera sempervirens) but also have more flowers over a longer period.
There is no one-size-fits-all answer on the issue of whether or not to include nativars in the garden.
Expect confusion, at least for now while researchers continue to sort through the details, nativar by nativar. I've yet to see a list of "good" nativars and "bad" nativars. Purists reject them all and opt for growing only unadulterated species. A more thoughtful but time-consuming approach is to check plant descriptions and reject only those described as being sterile, having double flowers or other attributes that could be a problem for wildlife.
As long as your garden includes a wide variety of plants, having a few that don't support wildlife shouldn't offend Mother Nature. In "The Living Landscape" (Timber Press, 2014, $39.95), authors Rick Darke and Doug Tallamy write that nativars function as native plants, as long as hybridization or selection hasn't changed their reproductive parts or chemical makeup.
For another view, search "Nativars" at wildones.org.
Contact the writer: www.midwestgardening.com