Care of Drought-Tolerant Landscape Grasses

Soil

• Give your landscape grasses the best chance of surviving a drought by planting them in well-drained soil that's been liberally amended with organic material. Loosen the top 10 to 12 inches of the soil with a shovel, spade or tiller, and incorporate a 4- to 6-inch layer of compost, peat or commercial soil amendment. This organic material acts like a sponge, absorbing water when it's available and releasing it slowly as the grass roots need it. Plants grown in well-prepared soil are much more drought-tolerant than those grown in hard, compacted soil.

Fertilizer

• Ornamental grasses need very little fertilizer, so feed them lightly in early spring just as the new growth emerges. Overfertilization encourages excessive growth that stresses the plants' root systems and makes them less drought-tolerant, as well as making the plants susceptible to disease and lodging, or falling open.

Water and Mulch

• Being drought-tolerant doesn't mean these grasses can do without water entirely. They require supplemental watering during extended dry periods and hot, windy weather, just not as often as other, less tolerant plants. If you see signs of water stress, such as brown or dried leaf tips, curling leaves, change in leaf color or wilting, give your grasses a slow, generous soak, enough that the soil is moist to a depth of at least 10 or 12 inches, more for very large grasses. A drip irrigation system with individual emitters at each plant is an efficient way to water large planting beds. Mulch the grasses with a 2- to 3-inch layer of organic mulch, such as grass clippings or shredded bark, to conserve water and keep the roots cool.

Establishing Drought-Tolerant Grasses

• Even the most drought-tolerant ornamental grass needs special attention while it's establishing itself in the landscape. Keep the soil moist, but not soggy, until you see new top growth, which indicates that the roots are establishing well. Gradually extend the periods between watering to acclimate the grass to drier soil. Don't fertilize a newly planted grass during its first season, as you want all of the plant's energy to be directed into root growth, not top growth.

Drought-Tolerant Selections

• Not all ornamental grasses are drought-tolerant. Most grasses native to the American prairies, such as Muhly grass (Muhlenbergia spp.), prairie dropseed (Sporobolus heterolepis) and little bluestem (Schizachyrium scoparium), are very tolerant of drought conditions. Sea oats (Uniola paniculata) and pampas grass (Cortaderia selloana) are also good choices for dry gardens. Many of the maiden grasses (Miscanthus app.) and fountain grasses (Pennisetum spp.) are also drought-tolerant, but check the label carefully, as the water requirement varies among cultivars.