By Carl Wilson, Extension Agent, Colorado State University Cooperative Extension in Denver County
Name a plant that provides foliage variety, interesting blooms, winter texture, movement and sound for the garden. Sound like too much to ask?
Not if the plant is one of the ornamental grasses. Most gardens can benefit from the vertical line and foliage contrast grasses provide. Both leaves and blooms sway in the wind providing movement in a static garden and additional interest from the gentle rustling sounds. The winter form of tan grasses against white snow is dramatic.
Americans have been late to discover the merits of ornamental grasses. This is ironic because many grasses native to the Great Plains are perfect garden candidates.
Prairie dropseed (Sporobolus heterolepis) grows three feet tall with emerald green leaves and cloudlike, sweet smelling blooms. It works well in hot, dry locations and attracts birds to the garden. Indian grass (Sorghastrum nutans) grows to five feet tall and produces eight-inch seedheads on stiff stems. The bronze flowers are good for fresh or dried arrangements.
If you're looking for russet red fall foliage color, Little bluestem (Schizachyrium scoparium) delivers. In summer, leaf color is blue-green to blue and the fluffy white seedheads make good cut flowers. Its Zone 3 hardiness makes it a good candidate for planting in mountain areas.
Grasses from other parts of the world also have found a place in American gardens. The wheatlike look of Eurasian Feather reed grass (Calamagrostis arundinacea `Karl Foerster') has made it very popular locally. Three feet tall, stiff and upright, this grass looks as well in formal gardens as in casual shrub and flower borders.
For a touch of the exotic, try Japanese blood grass (Imperata cylindrica `Red Baron'), a red and green groundcover that grows only 12 inches high and produces no bloom. Its spreading habit can be a problem, so contain it with barriers or in pots. It requires ample water and should be considered half hardy.
For a screen or the large landscape, Giant Chinese slivergrass (Miscanthus floridulus) offers much. It grows into a giant, eight-foot arching form and produces 10-inch, fluffy silver flowers.
Grasses are very adaptable, growing in poorer soils than many other garden plants. They require little effort to maintain other than to cut back to the ground in early spring before the new growth begins. This places them among the lowest care garden plants.
The world of ornamental grasses is much broader than the familiar fountain grasses (Pennisetum sp.) and maiden grasses (Miscanthus sp.). At least fifty true grasses are cultivated locally. Additionally, close grass relatives such as sedges, rushes and hardy bamboos offer the curious gardener endless possibilities.
Cooperative Extension and the Denver Botanic Gardens have developed a fact sheet about ornamental grasses adapted to Colorado. Contact the Denver office of Colorado State University Cooperative Extension to request a copy. Phone (303) 640-5278.
Photograph courtesy of Judy Sedbrook.
© CSU/Denver County Extension Master Gardener 2010
888 E. Iliff Avenue, Denver, CO 80210
Date last revised: 01/05/2010