Timberlines

By Shelly L. Van Landingham

Colorado State Forest Service

August 20, 2004

Xeriscape vs. Zero-scape

On average, 50% of household water is used in the landscape. It makes sense, in our semi-arid climate, to reduce the amount of water used in our yards: The concept of xeriscape can help accomplish this. Xeriscaping simply means reducing the amount of water used in your yard and/or garden by applying the following concepts: Planning and designing, improving soil, turf alternatives, selecting low water use plants, watering efficiently, using mulches, and maintaining your xeriscape.

Xeriscape does not mean Zero-scape: Often, when people hear the word xeriscape they picture a moonscape full rocks a few plants. Although this would significantly reduce your water use, it is not the typical xeriscape yard: Xeriscape yards can be very green and attractive.

In this article I will focus on just a few of the xeriscape concepts: Planning, turf, selection of low water trees and shrubs, and mulching.

It is useful to draw up a plan of the area or areas you would like to xeriscape. In many instances, this simply means sketching the project area. Planning will identify existing structures and plants, and give you dimensions to work with—all on a workable scale. Knowing dimensions will help you figure out the amount of plant, mulch, and irrigation materials you will need, and provide you with a cost estimate of the project. A plan will help you work out potential problems before investing time and money into something you may eventually discover is unworkable.

If you have a bluegrass lawn, consider reducing the amount of lawn area by using less water demanding plants such as drought resistant ground covers, perennial flowers, shrubs and trees in areas where the grass is hard to maintain such as on slopes, in shaded areas, or corners of your yard. Also consider replacing the bluegrass with native grasses such as buffalo and/or blue grama. Buffalo grass uses up to 80% less water than bluegrass on clay soils. Buffalo and blue grama should be seeded in late spring, when nite temperatures reach approximately 55 degrees. During the first year, these grasses will require regular watering to establish a dense turf. Once established, they can be weaned of regular watering, but intermittent watering will keep these grasses green and healthy throughout the growing season. Buffalo and blue grama also require less mowing, or no mowing at all. Unmown, these grasses will reach a height of 4-10 inches. Bluegrass requires at least 25 inches of supplemental water per season: Buffalo and blue grama need only 5 inches of supplemental water per season to remain healthy!

Tall fescue can also be used as a bluegrass alternative. It uses 50% less water than bluegrass, but still provides the green appearance. Other similar drought resistant species that have similar qualities to bluegrass include smooth brome, fine fescue, perennial ryegrass, and many species of wheat grass. Most of these grasses require about 12-18 inches of supplemental water per season.

Also, consider separating your turf area from other plantings. This adds to the appearance of your landscape and saves water by allowing you to water the turf separately.

When selecting your plants for your xeriscape project, be sure to choose varieties that are best suited for the climate you live in. Trees and shrubs are best planted in beds or islands separate from the lawn unless the lawn also requires low watering. Remember that trees and shrubs require deep watering to remain healthy and avoid insect and disease problems. Deep watering means establishing 8-12 inches of soil moisture when watering within the drip line, and letting the soil dry a bit before watering again. Avoid shallow frequent watering, such as running the sprinkler for 20 minutes every day—this will suffocate roots close to the surface and desiccate deeper roots, as they will not get enough water. Regardless of how drought resistant a plant is, it will still require relatively frequent watering until the plant is established. For most plants, this is two growing seasons. Once established, a gradual reduction of watering frequency can be accomplished. The following is a list (not comprehensive) of plants that tend to fair well in Southeastern Colorado's climate and soils in a landscape situation:

Deciduous, Larger: Western Catalpa; Liberty Elm; Hackberry; Honey Locust; Kentucky Coffee Tree; Bur Oak; Linden Varieties; Japanese Pagoda Tree; Bigtooth (Wasatch); Maple; Mulberry. Deciduous, Smaller: Crabapple and Apple Varieties; Hawthorn Varieties (usually has thorns); Golden Raintree; Ornamental Pears (Preferably Aristocrat); Japanese Tree Lilac; Winterberry Euonymus ; Purple Leaf Plum; Osage Orange (has thorns); Redbud. Evergreens: Juniper Varieties (Rocky Mountain, Utah, Oneseed); Eastern Red Cedar; Ponderosa Pine; Mugo Pine; Austrian Pine; Pinyon (only if preventive spray for Ips beetles). Shrubs: Juniper varieties (blue rug, tammy, pfitzer, buffalo etc.); Lilac; Nanking Cherry; Trumpet Vine; Native Plum; Sumac varieties (smooth, three-leaf); New Mexico Privet; Chokecherry; Rabbit Brush; Salt Brush; Sage varieties; Yucca varieties; Ground rose cover varieties; Rose of Sharon; Honeysuckle.