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Xeriscape for Drought-Tolerant Landscaping
Published 07/08/2008 by Julie Day
In our changing climate, water is becoming a precious resource. For many communities, municipal water restrictions are now commonplace, requiring innovative approaches to landscaping and gardening. One solution is xeriscaping, derived from the Greek word for “dry,” which employs drought resistant plants and water conservation measures to limit the use of irrigation in landscaping. Xeriscapes do not follow a specific design but apply a set of principles to determine the most efficient and pleasing layout based on the climate and topography.
Planning and Design
In order to work in harmony with the natural features of the land, a detailed plan is essential. A xeriscape plan differs from traditional landscaping plans in that it attempts to adapt to the existing features and climate, rather than forcing change through watering or amending.
Start by making a scale drawing of your yard and its existing features. Be sure to include your house, driveways, walkways, patios, trees, planting beds, spigots, downspouts, buried cables and drains. Take note of the slope of the land, sunlight and shade, and which areas tend to be wet, dry, windy, hot, humid, or cool.
The next step is deciding how you want to use your yard. Pencil in any new features, such as a vegetable garden, an area for pets, or a shady spot for relaxing. The final step is determining which types of plants are best suited for each area and how they will receive water.
If you are using only native plants, soil amendments may be unnecessary, and some plants actually thrive in poor soils. For most plants, however, a nutrient-rich, well-drained soil is essential to hold in moisture without drowning the plants. For flower beds, work 1 to 2 inches of compost into 6” or more of soil. Deeper planting holes for trees and shrubs should have compost or organic matter added as well. If your soil is particularly compact with clay, consider a drainage amendment such as Perma Till.
Rethink the concept of a traditional “lawn” since traditional turf grass requires a lot of water. Limit grass to walking and play areas, and consider the use of mulched or naturalized areas, along with patios and walkways, as alternatives. Do not plant grass where grass does not like to grow! Choose drought-tolerant grass suitable for your climate—such as zoysia, Bermuda, or buffalo grass—and plant during rainy seasons to minimize watering.
Using plants native to your area reduces the need for fertilizer, soil amendments, and irrigation. Xeriscaping uses the principle of “plant zoning,” in which plants are grouped according to water, light, and soil needs. This minimizes water waste and makes maintenance much easier. If you love certain plants that require lots of water, group them together close to a water source such as a drainage area or downspouts to make use of rainwater runoff.
As much as possible, choose plants that are drought and heat tolerant, particularly for dry sunny areas. Instead of irrigating an entire bed, tuck in containers for a splash of color, and water them by hand.
Using a layer of mulch around plants increases moisture retention and helps keep roots cool. See Using Mulch in Your Garden.
If there are areas that require extra irrigation, install drip systems or soaker hoses that conserve water by targeting specific plants. Avoid sprayer-type irrigation systems that waste water through evaporation and misting. Install water collection systems, such as rain barrels, close to plantings with higher water needs. Water after 9 p.m. and before 9 a.m. to reduce evaporation. Water less frequently but more deeply to encourage stronger roots that can withstand drought.
Xeriscapes require less maintenance than traditional gardens, because the detailed planning ensures that each plant will be naturally suited to the area. Nevertheless, routine weeding, pruning, irrigating, and fertilizing (if needed) are necessary to keep plants healthy and to reduce competition for nutrients and moisture.
For more about xeriscaping, check out the Denver Water Department website.
Maps showing the average rainfall in each state can be found at the Western Regional Climate Center.
Charts giving the average monthly temperature and precipitation for many cities and towns in the United States are available at Country Studies.
To check current drought conditions in your area, go to National Drought Mitigation Center