Gardening and Ornamental Grass

Features

• Ornamental grasses generally require little effort to keep them healthy. A commonsense solution for gardens that need groundcovers, erosion control or even a vertical or horizontal design element, ornamental grasses may be tall or short, colorful or muted, with textures that decorate and frame other features of the garden. Chosen wisely with advice from your local agricultural extension agency, benign species of ornamental grass will accent your garden display without overrunning it.

Uses

• Ornamental grasses range from 6 inches to several feet tall. Perfect accent plants and groundcovers, they also make good screens, borders or companion plants for flowers. The leaves of ornamental species come in all shades of greens, solid or variegated colors, and some even produce flowers -- usually small, but often quite colorful. After the season, grasses turn brown or light tan and dry out. Even then, the tufts of dried foliage and flowers remain attractive through the winter. Just make sure the dry foliage is not near something that could set it on fire. Dry grass is very flammable, and could set fire to your house or gazebo if touched off accidentally.

Types

• Native species grow naturally in your area. Grasses that grow native in other parts of North America but not yours should be treated like imported ornamental grasses. Among natives, taller species generally require more water, but for the most part, the normal rainfall in your climate is sufficient. Nurseries carry ornamental grasses that come from all over the world. Before buying imported varieties, determine first if they prefer a dry or wet climate and stick to one or the other. Mixed water requirements can cause problems, not only for your ornamental grasses, but for nearby flowers and herbaceous ornamentals. Rhizomatous grasses spread by underground stems, expanding up to 12 feet per year. Grasses like blue fescue, fountaingrass and purple moor grass form clumps and only propagate by division every two to three years. Aggressive rhizomatous types control weeds, provide groundcover and erosion control. Clump formers make nice, stable non-aggressive border plantings, invading neighboring spaces less readily.

Care

• Don't plant ornamental grasses in winter. Spring is best, but grasses start well in summer if thoroughly watered, as long as they're not bare-root varieties. Summer plantings allow time for roots to spread before winter. If you're starting ornamental grass in autumn, start it in containers at least a month before the first estimated frost. As a general rule, space plants as far apart as they are tall: plant 2-foot-tall clumps 2 feet apart. Division is the most practical way to propagate ornamental grasses. Hybrid varieties sold in nurseries won't breed true from seed, although most native species do. Some species even propagate from cuttings, but the process is more labor-intensive than with division. Check with your nursery about how to propagate the kind you bought. Grasses prefer soil pH from 7.2 to 7.8, but may tolerate a range of 5.0 to 8.0. They like well-drained soil and regular watering, and only need fertilizer during droughts. Mulching discourages weeds. Insects and animal pests tend not to bother them.