Flowering Grasses

About Ornamental Grasses

• The term "ornamental grass" covers a variety of plants that may or may not be a true member of the grass family. Ornamental grasses come in annual types that die over the winter, or perennial types that die to the ground and re-grow in the spring. Ornamental grasses may be clumping or spreading, and the cultivar's growth habit should be considered when planting. Spreading grasses use rhizomes to propagate and can quickly become a problem for other plants in the area.

Bluestem Grass

• Little Bluestem (Schizachyrium scoparium) is a 4-foot-tall clumping grass with gray-green foliage that turns to red or purple in the fall. It may retain color through the winter, depending on environmental conditions. Flowers with a feathery appearance bloom on upright stalks in August and September. A different variety of bluestem, called Big Bluestem, grows to 9 feet tall. Little bluestem grass grows in USDA Hardiness Zones 4 to 9.

Switchgrass

• Switchgrass (Panicum virgatum) comes in a variety of species that offer a number of colors from medium green to blue-green. It grows in a clumping habit to 5 feet tall with delicate pink or pinkish-purple flowers held erect above the foliage, generally appearing from July through September, according to the University of Illinois Urbana Extension Service site. Fall foliage color is golden or bronze. Switchgrass grows in zones 2 to 9.

Annual Quaking Grass

• Annual Quaking Grass (Briza maxima) grows to a height of 2 feet with thin stems and fluffy, overlapping green-tinged seed pods that quiver with every passing breeze. These are attractive in dried flower arrangements. It grows easily from seed for an attractive display of silver-white flowers. Annual Quaking Grass grows in zones 4 to 10.

Blue Lyme Grass

• Blue lyme grass (Leymus arenarius), grows to 3 feet with wide-leaved, clumping blue-gray foliage. The narrow flower stalks start out whitish-blue and pale to a beige color in the fall. It will stay green until temperatures fall into the teens. Clumps can become invasive, spreading out rhizomes up to 8 feet. Blue lyme grass is hardy in zones 4 to 10.

Special Considerations

• Divide clumping grasses that have become too large for their location in the fall. Some states prohibit certain varieties of spreading ornamental grass because their invasive properties can crowd out native grasses, according to Colorado State University horticulturalist C.R. Wilson. Consult your local agricultural extension service for information on ornamental grasses that are considered troublesome weeds in your area.