Ornamental Grasses In The Landscape
Mary Anderson Master Gardener: In the dog days of summer, it´s hard to get excited about what´s happening in the garden, especially as Bambi is now seriously knocking at (or jumping over) the garden gate. However, some of my favorite plants are just beginning to strut their stuff. These are the ornamental perennial grasses.
The German horticulturalist Karl Forster described these grasses as “the hair of the earth.” Few plants express an almost visceral connection to the natural landscape as do grasses.
The structure of a meadow is in its grasses. The perennial bunch grasses of the flower fields that awed John Muir as he made his way across the Central Valley. The rushes and sedges of wet mountain meadows abloom with orchids, mimulus, elephant heads and iris. The magnificence of the American prairies where blue stem, feather reed grass and panicum shelter penstemon, liatris, rudbeckia, echinacea, solidago and aster.
Ornamental grasses bring features like movement and sound to a garden. They create architectural interest with verticality or sweeping forms. They dance in a breeze, whisper in the morning wind. I love to feature a large clump of grass as a specimen plant and skirt it with a companion of contrasting leaf shape, like the sedum ‘Autumn Joy´ with the tall elegant Miscanthus sinensis ‘Gracillimus.´ Or marry the Flame Grass, Miscanthus purpureus with a close color combination like Berberis t. ‘Crimson Pygmy.´
One of the most stunning ways of featuring a grass is to focus it in a container—an upright pot with a spray of Juncus effuses ‘Carmen´s Japanese Sedge.´ Or a terra cotta pot crowned by a sweep of New Zealand Weeping Brown Sedge. A breathtaking display is a glazed black pot with ‘Frosty Curls´ Blond Sedge sprouting from it.
Grasses honor the change of seasons. A plant like Miscanthus s. ‘Malepartus´ begins in spring as an upright clump of stiff green leaves. Mid to late summer, flower stalks rise above the four-to-five-foot-tall clump of foliage, with the silver inflorescence drying to fluffy white. In the fall, the foliage colors to gold, with infusions of red and orange, then pales to almond after the frost. Rimed with frost or topped with a hat of snow, the clump keeps interest until it is time to cut it down in winter before the new growth begins. Its only quiet time is mid-January through early March, but I surround the clump with daffodils to remedy this.
Ornamental grasses are very low maintenance. Cut the deciduous ones back almost to the ground before new spring growth starts. For me, this is mid-January. Comb out (with gloved fingers or a cheap wide-toothed plastic comb) the perennial ones. Deadhead stipa and fescue when you get around to it.
And now the best part—most grasses are DEER PROOF. Bambi cannot deal with the tough siliceous leaves. Bugs don´t bother them and diseases head for your precious perennials. And, because they are green, growing and watered during the summer and fall—our fire season—and do not dry out until after the frost (end of fire season) they are not the hazard that the annual wild grasses are.
Among my favorite grasses are the California native stipas or nasselas. Purple Needlegrass is the California state grass. These are beautiful in wildflower meadows or as a groundcover in the dry shade under oaks. Deer grass, or Muhlenbergia rigens, was so named not because deer eat it, but because the mama doe will shelter her newborn fawn under the sweeping clumps when she goes to browse. Deer grass forms large mounding clumps with tall flower spikes from mid-summer on. I use deer grass as accents in a sea of low growing Ceanothus ‘Anchor Bay´ for a stunning contrast.
Wonderful specimen plants, especially for the higher elevations where their fall colors are most pronounced, are the Japanese and Korean Miscanthus. ‘Gracillimus´ is tall and graceful, with finely textured foliage and copper-red flowers in September. ‘Morning Light´ is a form with fine, narrow, white-variegated foliage, and reddish flowers. Check with your local nursery for other cultivars, in a variety of tones, heights, and bloom times.
Among the “evergreen” (or gold, brown, bronze, etc.) grasses are the showy carexes. New Zealand plants have something against green, for some of the most colorful forms come in shades that Miss Clairol could barely describe. In our family, these were known as the “good hair day” grasses. They thrive in average soil, with some afternoon shade, and are perfect features in the perennial border.
Mention should be made of the wonderful blue foliage grasses, like Blue Oat grass and blue fescue, which are useful in Mediterranean landscapes with lavender, ornamental oregano, germander and thyme.
My favorite reference book for these wonderful plants is The Color Encyclopedia of Ornamental Grasses by Rick Darke. The California Native Plant Society has a newly released poster featuring our native grasses. It is available at chapter meetings or the semi-annual plant sales. See you in the garden.
Mary Anderson is a master gardener in Calaveras County. She is a member of the California Native Plant Society and grows, sells, and advocates the use of native plants in foothill gardens.