Eco-type, species, nativar: Nuances of native plants

The plant sale that I wrote about in my last column, a joint effort of Lindera Nursery and Tiny Meadow Farm, was fantastic. I came home with pots of rattlesnake master, Eryngium yuccifolium, which I planted in the meadow with the hope that their tall glaucous leaves and round balls of white flower will punctuate the otherwise mostly grassy green expanse. For a shady spot left by transplanting a witch hazel, several pots of Jacob’s ladder, Polemonium reptans echo the tones of the violet and bluebells nearby.

I added two plants to the river path beds: Echinacea pallida — a restrained looking echinacea with thin pale pink petals that drape downward, and obedient plant, Physostegia virginiana, whose whitish- pink upward- growing flowers are reminiscent of snapdragons or lobelia. These should fill in alongside the existing penstemon, mountain mint and the low growing, shocking-pink Silene caroliniana that is flowering right now.

Not only are all the new acquisitions native, most of the plants are also local eco-types; the seed from which the plants were grown was came from plants grown locally. The thinking is that insects and birds are accustomed to the particular tastes, smells, shapes and colors of local plants and so, from the perspective of habitat preservation, they will have the best opportunity to succeed. Even humans, who are the most adaptable species, can relate to this notion: one person’s award-winning three-alarm chili is another person’s digestive nightmare.

On the other end of the native plant spectrum are the cultivars. These are versions of native plants, selected and bred because they have an appealing aesthetic or disease resistance that differs from the original species. Some cultivars are strains of native plants found in nature and are grown from seeds from these plants, others, mainly woody plants, are created by cloning using plant cuttings.

Also called nativars, they are most often what you will find in nurseries and garden centers when looking for native plants. A cultivar, native or not, will always have it’s specific name in quotation marks; this is the best clue to identify it as a cultivar. Producers are allowed to trademark cultivars of plants, such as ‘Balmy™ Purple’ Bee Balm which is one of the many nativars bred and sold under the American Meadows brand.

I succumbed to this mild-mannered marketing about ten years ago, well before I really paid attention to native plants, when purchasing a redbud nativar that has deep purple leaves, rather than the green leaves of the species. Even if the nursery had carried the species, I would have selected this one; I was seduced by its name, ‘Forest Pansy’, as well as the charming color and shape of its leaf.

What I did not know at the time, and wish I had, is that nativars with purple or red leaves are far less interesting as a food source to caterpillars than are the original green leaves of the straight species. The chlorophyl of the green leaves is replaced by anthocyanins, flavonoids that, while healthy, are ‘feeding deterrents’ according to Doug Tallamy who did the research with Mt. Cuba, a botanic garden and research center focused on native plants. Mt. Cuba’s research team looks at native species and their cultivars, assessing them over many years and then rates them for considerations including growth habits, hardiness and habitat benefits.

I spoke with Melissa Starkey, Ph.D., from Mt.Cuba who agreed that “there seems to be a lot of misinformation floating around that cultivars are ‘bad’ though in our research sometimes they are the winner for pollinators.”

What do we need to take into account when making a decision about a nativar, so that we end up with a plant that, in addition to being pleasing to us, is helpful to caterpillars, bees, other insects and birds? Apart from avoiding red and purple cultivars of green-leaved native species, Melissa advises that we be aware of nativars cultivated to have double or triple rows of petals. These plants, while more decorative forms of the original species, are far less attractive to pollinators. Some cultivars, such as mophead hydrangea, have mostly sterile flowers and therefore are of little use to bees and other pollinators. Lacecap hydrangea, such as Mt. Cuba’s highly rated ‘Haas Halo’, is a haven for pollinators.

To compensate for the three Ninebark ’Coppertina’ shrubs I had planted 8 years ago, Robin Zitter, the horticulturalist who helped me create the river path, wisely advised that I plant a few straight species alongside these deep coppery red-toned nativars. Robin sourced one plant and the others came from Earth Tones, a wonderful source for native plants in Woodbury.

Our sources for native plants have improved over the last few years and seeing examples of the beautiful native flowers, shrubs and trees has encouraged many to seek them out. We can aim for the local ecotype of a species when available to us and strive to plant native species first and nativars second.

Dee Salomon “ungardens” in Litchfield County.