In the more than four years of this column, I have written few words about ornamental grasses. I have a “been there, done that” feeling — the plants and the garden style that brought them into vogue just don’t interest me anymore.
I went through a period of infatuation with ornamental grasses during the 1970s when they were first introduced to gardeners in this country, when species from Asia and Europe, and cultivars of those species, were massed in borders across the South and mid-Atlantic states while being touted as the backbone of the “New American Garden.” Garden magazines (as well as a book by Carole Otteson titled “The New American Garden”) published images showing tall clumps of variegated miscanthus or pennisetum exploding from expansive drifts of Sedum ‘Autumn Joy’ and Rudbeckia ‘Goldsturm.’
There was nothing American about these landscapes. Having destroyed our native prairies, we responded to our collective genetic memory and the innate desire to look out over wide expanses of grassland by filling our landscapes with non-native grasses and forbs.
Then we learned that some of the non-native grasses that we had planted, including species of Miscanthus, maidengrass, Pennisetum, fountain grass, Imperata, Japanese blood grass, and Cortaderia, pampas grass, were invasive, colonizing roadsides and the shores of reservoirs, establishing populations in forests and old fields following fires. Sadly, this knowledge has not stopped the production, promotion, or planting of invasive grass species, but some of us have taken another look at what would be growing in a truly native landscape.
There is a native grass in Marjorie’s garden. I don’t know its name, but at the moment it sends its slender flowering stalks about two feet into the air to be stirred by the slightest breeze. Over the years it has formed a respectable patch surrounded by a colony of rough-stemmed goldenrods topped with bright yellow tassels, several mapleleaf viburnums with terminal clusters of small green berries that will soon shrivel to raisins, and a stand of common elderberry with fruits just starting to go purple, all native species. I can look down on this landscape from the porch and realize that it scratches that genetic itch for me.
I can look a little farther out to a group of summersweet clethras, Clethra alnifolia, the pink-flowered cultivar ‘Rosea’ in full fragrant bloom, and in front of these shrubs, growing out of my dragonfly pot, a fountain of slender bronze-colored leaves, Carex comans ‘Bronco.’ A non-native member of the sedge family, this single grasslike annual provides the perfect contrast in texture and color to the pink flower spikes of the native summersweets.
Still farther out from the porch, in the sun of the perennial garden, is an old terra cotta pot, weathered to a patchwork of green paint and raw red clay, planted to three non-native annuals: a deep pink twinspur, Diascia, a purple-leaved sweet potato vine, Ipomoea batatas, and the fiber optic grass, Isolepis cernua, another fine textured sedge with arching wiry leaves and tiny white flowers at the leaf tips that resemble fiber optic lights set at the end of thin wires. I selected the sedge first, intrigued by its habit and texture, and then chose the sweet potato vine and twinspur to provide contrast.
I found both of these sedges at Everlasting Farms in Bangor, the garden center to visit in early spring for unusual annuals. With no record of invasiveness in any region of the world and cold hardy only to USDA Zone 7, there is little risk to natural areas when using either of these sedges in a Zone 5 Maine garden. At the end of the gardening year, I will toss them on the compost pile with a clear conscience.
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