Do nativars, cultivars of native plants, have a place in your wildlife garden? They do in mine. And also in many of the gardens I design for my clients. Sometimes, a cultivated variety of a native plant can be easier to combine in a garden. Lets face it, not everyone has space for purple Joe-Pye weed (Eutrochium purpureum) that can grow to 7 tall or more in their garden. But they may be able to grow the more compact cultivar Gateway (Eupatorium purpureum subsp. maculatum Gateway). It still reaches heights of 4 5 though, so compact is clearly a relative term.
The Issues with Nativars
Nativars, whether open-pollinated or hybridized, are chosen by growers because they offer something new and different flower or leaf color, a more compact growth habit or improved disease resistance. While they may perform better in your garden, they may not offer all the ecological benefits that straight species plants offer. And relying solely on nativars can mean less genetic diversity in your garden. And depending on whats new & improved about your nativar, it could mean nectar and pollen is not available or that leaf chemistry has been altered so much that they are no longer of any benefit to insects.
Is it better to not plant a native plant than it is to plant a nativar? Does the use of native plants have to be an all or nothing proposition? My sense is that there are as many answers to that questions as there are gardeners. I wont go into all the issues surrounding nativars since the topic has been expertly explored already in by Sue Sweeney in The Nativar Dilemma.
As wildlife gardeners, we want plants that are colorful, bloom for a long time, look good in our gardens and nourish the local wildlife. The heart of the issue with nativars is whether or not they really are acceptable alternatives to the native species for insects and small animals that feed on plants. The answer is sometimes, but not always. Frankly, well never know the answer for each and every nativar that seems to popping up on the nursery benches lately.
Fortunately, there s a great deal of research happening now comparing straight species plants to many of their cultivars. Here are some of the studies Im keeping my eye on. Some are evaluating the vigor and garden-worthiness of nativars while others are evaluating the pollinator value of cultivars.
Mt. Cuba Center Observing Pollinators on Annual Coreopsis
Penn State Extension Pollinator Plant Trials
University of Vermont Evaluation of 14 Native Species and Nativars
Mt. Cuba Center Aster Evaluation
Mt. Cuba Center Baptisia Evaluation
Mt. Cuba Center Echinacea Evaluation
University of Vermont Echinacea Hardiness
While waiting for the research results to be published, I tend to err on the side of caution. This philosophy is best summed up by fellow NP&WG team member Vincent Vizachero in his post Native Cultivars Good, Bad & Ugly, my first choice will always be a locally-sourced open-pollinated seed-grown plant. My second choice will be a cultivar that maintains the flower shape, berry size, and leaf color of the species. My goal is to never buy cultivars that exhibit radically different flower shape or color, but I will knowingly buy dwarf varieties which are otherwise similar to the species. And when I see a cultivar touted as resistant to insect damage, that one gets an automatic rejection.
Are you watching any nativar evaluation trials in your area?
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