Water has become a critical issue for most Texans. And while recent rainfall has raised area lake levels and eased local water restrictions; booming populations are increasing the demand on the areas limited water supply. Seasonal fluctuations in rainfall and periodic droughts create a feast-to-famine cycle for residence living in the Coastal Bend. In urban areas, about 25 percent of the water supply is used to water landscapes and gardens. In the summer, as much as 60 percent of the water the average household uses may be used for landscape maintenance. Many landscapes require large amounts of water and much of this water is applied inefficiently. While adopting efficient lawn irrigation techniques can help save large amounts of water, a comprehensive program of landscape water conservation can dramatically reduce landscape water demand.
This idea is better known as Xeriscape landscaping but it need not be all cactus and rocks. A Xeriscape landscape has plenty of room for lush turf grass and shade trees. There are seven water saving principals of Xeriscape landscaping: planning and design, soil analysis and preparation, practical turf areas, appropriate plant selection, efficient irrigation, use of mulches, and appropriate maintenance. None of these practices are new and by incorporating these seven principles, you can help preserve our most precious natural resource - water.
Planning and design is the starting point for any water wise landscape. Consider how you use the various areas of your yard, how you want your yard to look, the amount of maintenance you plan to give it, and the budget you can afford. When designing the landscape, keep in mind that turf grasses need more water and maintenance than most other plants. To conserve water, reduce the size of the lawn by including patios, decks, shrub beds and groundcovers in the landscape design. Also consider the ease of watering turf areas. Areas that are long and narrow, small, or oddly shaped are difficult to water efficiently. Confine grass to blocky, square areas that are easier to maintain. The purpose of planning is to design a landscape that will have the appearance and function you desire while conserving water. You can implement your landscape design gradually over several years.
Prepare your soil by starting with a good soil test. Soil analysis will show whether the soil should be improved so that it will absorb and hold moisture better. Most soils benefit greatly from organic matter. Adding organic matter to the soil of shrub and flower bed areas makes plants healthier. Organic matter also helps the soil absorb and store water. As a rule-of-thumb, till in 4 to 6 inches of organic material such as shredded pine bark, compost or leaves.
Select trees, shrubs and groundcovers that are adapted to your region's soil and climate. The use of native plants in Texas landscapes has become extremely popular. Combining Texas natives with well adapted exotic plants is one key to a beautiful, interesting landscape that conserves water. Native plants generally use less water than exotic plants, but there is room for both in well-designed landscapes. Native Texas plants are becoming more available at retail nurseries and garden centers.
While tremendous amounts of water are applied to lawns and gardens, much of it is never absorbed by the plants and put to use. Some water runs off because it is applied too rapidly, and some water evaporates from exposed, un-mulched soil. But the greatest waste of water is applying too much too often. When too much water is applied to the landscape it can leach nutrients deep into the soil away from plant roots, and possibly pollute groundwater. Runoff also can cause pollution by carrying fertilizers and pesticides into streams and lakes. These problems can be eliminated with proper watering techniques. The key to watering lawns is to apply the water only when the grass needs it, but thoroughly saturating the soil profile to a 6 inch depth with each watering.
In addition to irrigation scheduling, irrigation application methods can be improved to decrease water usage. For tree and shrub watering around the dripline (the area directly below the outermost reaches of the branches) is highly efficient, not watering at the trunk. Simply lay a slowly running hose on the ground and move it around the dripline as the area becomes saturated to a depth of 8 to 10 inches. If you use sprinklers to water turf, make sure the sprinkler heads are positioned properly to avoid watering sidewalks and driveways. Also adjust sprinkler heads so that they spray large droplets of water instead of a fog or fine mist, which evaporates quickly and may drift away with the wind. Water between late evening and mid-morning so that water will not evaporate quickly and be wasted. Drip irrigation is an alternative to sprinkler irrigation systems that is highly efficient. Efficient irrigation can save 30 to 50 percent of the water bill for an average home.
Use mulch in flower and shrub beds to reduce water evaporation from the soil. Mulch is a layer of nonliving material covering the soil surface around plants. Mulches can be organic materials such as pine bark, compost and woodchips; or inorganic materials such as lava rock, limestone or permeable plastic (not sheet plastic). Use mulch wherever possible. Good mulch conserves water by significantly reducing moisture evaporation from the soil. Mulch also reduces weeds, prevents soil compaction, and keeps soil temperatures more moderate.
Good maintenance preserves the beauty of the landscape and conserves water. Mowing grass at the proper height conserves water because it encourages root systems to grow deeper and become more water-efficient. Fertilizing the lawn at the proper time and using the proper amount can save time, effort and money by reducing mowing and watering. Properly time any insect and disease control measures, and eliminate weeds. A well-designed landscape that uses Xeriscape principles can reduce maintenance by as much as 50 percent through reduced mowing, once-a-year mulching, the elimination of unadapted plants that require lots of water, and efficient irrigation.
Xeriscaping conserves water in the landscape without sacrificing beauty and plant diversity. The information in this article was adapted from Extension publication B-1584 “Xeriscape: Landscape Water Conservation.” For more information on Xeriscape landscaping contact our office at 361.767.5223
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