The Nativar War

A landscape architect once told me: "I like native plants. Especially slightly improved varieties, if you want to work on those." I had mentioned my interest in plant breeding, as well as natives in particular, when he articulated his preference for nativars.  The simple portmanteau "nativar" (native + cultivar) has proven divisive, pitting horticulturists against naturalists in recent years.

Just picture the scene: on one hand is a man with a career dedicated to the design of beautiful landscapes. He recognizes the ecological benefit of using native plants in his schemes, but he also wants to ensure that these plants can be aesthetically appreciated-- so he picks established nursery-propagated clones noted for a particular color or form. On the other hand is the proprietor of a native plants nursery. Her motivation is providing native plants for naturalists to use in restoration projects, as well as for anyone seeking to create a native landscape scheme. She grows all of her plants from seed, and won't carry any selected cultivars, since that would limit genetic diversity, and make her offerings less suitable for restoration purposes.

Echinacea purpurea (CC)

These differences aren't irreconcilable-- in fact, there really is no controversy in our hypothetical situation, since each person uses the plants suited to their particular projects. Seed-grown straight species for restoration and landscaping purposes; "nativars" for use in landscaping when the resilience of native species is appreciated, but greater diversity in appearance is desired. Where's the "war?"

E. purpurea 'Evan Saul' or 'Sundown,' a nativar. Photographed by Mike Peel (CC)

Some naturalists make de facto categorical denunciations of all nativars (although I don't want to paint with too broad a brush and make categorical denunciations of my own-- more moderate stances do exist). They make some legitimate points, but I think that a lot of the species-only naturalists' criticisms of nativars don't hold up when well-informed end users of nativars know exactly what they are doing. This is especially the case when we consider that some nativars are complex hybrids with a native species or two somewhere back in the lineage, whereas others are naturally-occuring variants or F1 hybrids, perhaps with unique coloration or double flowers. It's clear that the latter have more ecological function and should not be grouped with the more distantly-native varieties.

Now I'll summarize some of the most common arguments employed against use of nativars, as mentioned in the article "Native, or Not So Much?":

1. "Propagating clones inherently limits genetic diversity. This is bad since it inhibits the species' ability to cope with environmental stresses through evolution. Our selection of 'nativars' constitutes unhealthy artificial selection, and should be avoided." 
• This statement is essentially true, meaning that nativars should never be used as substitutes for unselected, seed-grown species in restoration projects, when this better, more natural alternative is available (even though I find the idea that planting genetically-identical clones has some objectively-measurable effect on species' success suspect). But this has no bearing whatsoever on their use in gardens; an ornamental plant with native genes can be grown and appreciated in the very same way nonnative ornamentals can be. 
2. "Certain forms lack the pollinator compatibility, nutritional value, or distinct wildlife-recognizable appearance of the species, and thus should be avoided." 
• True for restoration, but not applicable for the gardener who knows what he's planting.
3. "Selling seed-grown straight species is 'preservation' and is commendable. Cultivars, however, do not have the same ecological value as straight species; therefore, their preservation is less important." 
• I frequently find this argument implicit in discussions of nativars and native gardening. "Genetic diversity" is the name of the game in the natives trade-- except on many occasions when cultivars aren't recognized as legitimate units of genetic diversity because they have relatively little ecological value. The unfortunate result of this mantra is the removal of many interesting cultivars from native nurseries. Once I was looking for a white-variant of a plant for several years, and found a nursery that was in the process of discontinuing it, on the grounds that their propagation of the white variety was "artificial selection." The worst-case scenario would be a dichotomy of mainstream nurseries selling nonnative ornamentals, and native nurseries with proprietors that have been shamed into selling nothing but seed-grown straight species, with no commercial source for nativars.

Is the "nativar war" just an annoying result of today's environmentalist alarmism, or do nativars actually present an ecological threat? I think it boils down to knowing what you're planting-- recognize that certain nativars have some ecological value, while others are basically just ornamentals. Additionally, always plant the straight species when ecological function is paramount. What some naturalists fear-- legitimately-- is that confused consumers will assume that the prettier nativars are just as good for wildlife as the species, and consequently won't plant the species. But the solution is not a shunning of nativars.

The common orange coloration of Asclepias tuberosa (CC)

A yellow form of A. tuberosa (CC); a yellow form called 'Hello Yellow' is often seen in nurseries.

But as to my personal preference-- I often find that the highly-developed nativars are a bit garish. Graham Stuart Thomas pointed out, "[A] fundamental truth is that mankind is, by nature, greedy and dissatisfied with what nature offers."