Growing and Using Ornamental Grasses

Ornamental grasses are versatile garden plants without being fussy about care and maintenance. In the spring and summer they bring color, texture, and an airy, casual appearance to garden spaces. In the fall and winter, grasses can be left in the garden to provide structure and movement, or they can be cut, dried, and brought indoors for display.

Design Considerations

From a design standpoint, ornamental grasses are often combined with other plants such as evergreen shrubs, and perennial and annual flowers. They work well in beds, borders, rock gardens, edgings, or as specimen plants. When choosing grasses for your garden, carefully consider design elements such as size, color, texture, and form-the same as you would if selecting any other type of plant. Their delicate foliage comes in various hues of green, blue-green, cream, red, or variegated green on yellow. In the fall, the foliage typically turns to a light brown, which adds structural interest and movement to an otherwise barren winter landscape. Depending on the species, grasses can range in height from several inches to several feet tall.

Caring for Ornamental Grasses

Site and soil conditions: Belonging to the grass, sedge, and rush families, ornamental grasses are not very demanding plants. They will grow in a wide range of soil conditions (although rich soil is best) and have few, if any, disease or pest problems. They perform best in full sun, although in warmer parts of the country many species will also tolerate light shade.

Although a few species prefer moist, boggy conditions, most ornamental grasses are drought-resistant and can stand prolonged periods of dry weather. Most ornamental grasses are perennial plants. Annual grasses will need to be planted each spring, by sowing the seed directly outdoors into prepared beds.

Maintenance

Trimming: To keep ornamental grasses looking their best, give them an annual trim to remove the previous season's dead foliage. Do this in the early spring, just before new growth begins, so you don't lose the benefits of their attractive foliage over winter. Cut the plants back to the base; short grasses to 1 to 2 inches, and tall, clump-forming plants to 6 to 8 inches.

Division: Unlike most perennial garden plants, ornamental grasses can grow untouched for 10 years or more before they need to be divided. When it is time to divide them, use a garden fork to lift out the clumps and separate them into smaller parts. For the large, well-established species, you need may need a sharp knife (or even a saw) to cut through the tough, fibrous clumps and divide them into smaller pieces.

Harvesting Grasses for Display

Many ornamental grasses are prized for their beautiful flower and seed heads, which make a striking addition to seasonal flower arrangements. Big quaking grass (Briza maima), feathertop (Pennisetum villosum), and foxtail millet (Setaria italic) are three of the more popular annual grasses grown for their seed heads. Perennial grasses such as maiden grass (Miscanthus spp.) and pampas grass (Cortaderia selloana) are often used in autumn and winter displays.

To harvest ornamental grasses, cut the stems just before the seed heads open, tie them in small bundles, and hang them upside down to dry in a warm, dry room. If you prefer the look of a slightly curved stem, stand the stems upright in a tall vase (or section of PVC pipe) while they dry. Delicate seed heads can be preserved by spritzing them with a little hair spray so they don't fall apart.