By Dr. James R. Feucht, Extension Professor, Horticulture, Colorado State University
Less is more -- and better -- when water is involved. Cost increases, as well as shortages thanks to a low snow-pack, make water conservation a priority in 2002. With a few tricks, you can cut water consumption and still maintain a beautiful yard.
Check your sprinkler system. After danger of frost is past, turn it on, and observe where the water goes. Adjust sprinkler heads to point water where it is needed. In some cases, a different type of head may be in order. Most sprinkler systems are designed to water a lawn, but often they overlap and irrigate shrubs, trees and flower gardens that need less frequent watering. You may need to change entire portions of your sprinkler system to gain control over location and frequency of watering.
North exposure lawns do not need as much water as south or west exposures. Change your sprinkler system to occasionally skip waterings on north exposures, and to provide more water to sunny areas.
Most systems sprinkle in a circle or semi-circle pattern. Change your lawn to fit the sprinklers. Do away with corners that often are skipped. In place of lawn, consider ground covers that, once established, require little or no water. Creeping junipers, sedums and the old-fashioned hen-n-chicks do the job well.
Avoid large areas of gravel and plastic. While this method decreases lawn, it does not necessarily reduce water consumption. Light-colored gravel reflects a lot of heat and can create a microclimate resulting in greater water loss from the surrounding lawn. Black plastic over shrubs and trees creates oxygen starvation, causing these plants to develop shallow roots just beneath the plastic. After a few years, even drought-enduring trees such as Russian-olive develop shallow roots and lose their drought-tolerance. Plastic and gravel, therefore, are self-defeating. The new "breathable" fabrics are a better choice.
Wood chips or bark chunks, used without plastic or fabric, make a good mulch. These decorative materials allow air and water penetration, yet keep the soil cool. Heavier bark chunks are best in strong wind areas. Light weight wood chips will blow. Apply these mulches at least four inches deep to conserve water, as well as to discourage moisture loss and weeds. Over a period of time, materials closest to the soil will begin to break down to improve the soil. Add new chips after a few years.
Use drought-tolerant plants to reduce water consumption. Keep them separate from lawn and other plants that require more water. Design a succulent garden. Desert plants and nearly all succulents must have sandy, well-drained soils, of which there are few in Colorado.
With some effort you can convert your soil. Put three inches of coarse sand on top and incorporate it with a rototiller. Repeat using one inch of organic material such as aged barnyard manure or peat moss. This provides a well-drained top soil six to nine inches deep. Along with cacti and other succulents, consider gazania for a splash of color. This low-growing, drought-tolerant plant grows readily from seed and produces large showy flowers. Another choice is Cape Marigold, often called African daisy. This almost forgotten annual comes in a variety of colors including yellow, apricot and white. A variety of sedums or stonecrops also will produce interesting foliage, texture and color changes. Dragon's blood is one of the most popular. It produces a rose-red flower during the summer months.
Before you water, dig down and find out if the soil is dry. Don't gauge water needs on soil surface appearance. In this semi-arid climate, the surface dries quickly, but evaporation slows beneath. This is because dry soils tend to insulate, acting much as mulch. This insulation reduces heat conduction deep into the soil.
Black organic soil also is desirable, but it builds up heat and can be a water waster. Dark soils absorb heat and can need water as frequently as light-colored soils. The type of organic material makes a difference. Many mountain peats create a water problem. When they're dry, they are difficult to wet and they repel water. When they are wet, they are difficult to dry. The best organics to improve water-holding capacity are coarse materials such as compost and barnyard manures.
Photograph of red carpet sedum courtesy of Judy Sedbrook.
© CSU/Denver County Extension Master Gardener 2010
888 E. Iliff Avenue, Denver, CO 80210
Date last revised: 01/05/2010