Landscaping and water conservation may seem to be opposites, but in our desert areas, landscapes cool and modify the microclimates in and around homes and other buildings. Water conservation is essential because the supply is always limited. A water-efficient landscape helps conserve water and preserve beneficial aspects of plants.
A water-efficient landscape design starts from the ground up. Utah soils require amendments to provide aeration and proper drainage. If you fail to improve the soil, a low-water landscape will not succeed. Soil amendments loosen and allow better moisture penetration on heavy clay soils and hold more moisture on light, sandy soil. This reduces the need to irrigate.Landscaping, water conservation and energy conservation are also directly related. Each has a direct and dramatic effect on the others. In the name of conservation, well-meaning individuals rip plants out on the south or west sides of buildings and replace them with rock, plastic and gravel. These are often visually unattractive and usually increase temperatures inside the building and cause water to run off steep slopes. Drought-resistant ground covers reduce water loss and shade the soil. Strategically placed trees also cool the soil, resulting in less evaporation. Terraced slopes save water by slowing the runoff and allowing more water to soak in.
Almost everyone agrees that turf grass requires substantial water to keep it green. If the only time you walk on turf is to mow it, consider replacing it with something else. Other plants often use less water and require less maintenance, which in return requires less energy. Plant turf grass where it will be used. Other areas may contain drought-resistant grasses, flowers and/or shrubs.
Proper irrigation can save 30-80 percent on outdoor water use. If you already have a sprinkler system, check the coverage. If areas are not being properly watered or if water covers hard surfaces such as driveways or patios, the system needs to be readjusted. Heads may need to be replaced, additional heads added or the configuration changed to make the sprinkler system more efficient. Check if water is running where it is not needed. Adjust the sprinklers so that turf grass is irrigated separately from shrubs and flower beds. Northern and eastern exposures need water less frequently than southern or western exposures. Apply water more slowly on sloped areas than on flat surfaces.
To measure the amount of water applied, get several gallon cans and place them at random distances from the heads. Run the system for 30 minutes and then measure the water in each can. If you collect the same amount of water in each can, you have a very efficient sprinkler system. Normally, the amounts vary considerably, meaning your sprinkling system is less efficient. Since sprinkler systems are always run to water the driest spot, it is important to make the systems as efficient as possible. When designing a sprinkler system, get a professional design so that the heads are properly aligned and zoned. This means your landscape plan must be done prior to the time the sprinkler system is installed.
Drip irrigation also saves water. Drip systems continue to be improved each year and work well on narrow strips, shrub borders, raised planters, around trees and shrubs or in home orchards and vegetable gardens. About the only place drip irrigation won't work well is in turf grass.
Although most of us want a wonderful, lush landscape, it may not be possible to do this ecologically. Avoid frequent, shallow sprinkling that leads to shallow root development. Highly compacted soils don't absorb water, so aerate turf grass, particularly on slopes.
Avoid watering during the middle of the day. Temperature and wind are usually highest then, so evaporation is greatest. Early morning is best because it is cooler and the air is usually calmer.
Mulches also conserve water. They decrease soil temperatures and evaporation. They also discourage weeds. Weeds grow so quickly they use more water than desirable plants. Keep them out to further improve water conservation.
As vegetables mature and stop producing, remove the plants and cut off the water if possible. This reduces weed growth and helps conserve water.
Conserving water is every gardener's business. If water is not conserved, the ultimate problem will be no water in or for the garden. Avoid that problem by conserving water, soil and energy. It is the right thing to do.