Proper maintenance is a key principle in reducing irrigation requirements in the landscape. Maintenance practices, such as mulching, mowing, and fertilizing greatly impact the water efficiency of any landscape, as well as the landscape’s ability to survive a drought. Research at Texas A&M University has shown that un-mulched soil may lose twice as much water to evaporation as mulched soil. Mulch is a layer of material covering the soil surface around plants. Mulches can be organic materials, such as shredded bark, compost and wood chips; or inorganic materials, such as lava rock, limestone and woven plastic. Use a mulch whenever possible. A good mulch preserves soil moisture, prevents soil compaction, keeps soil temperatures more moderate and reduces weed populations. In case weeds do get a start, they are much easier to pull when mulch has been used. Organic mulches will decompose and sometimes wash away, so make checks regularly and replacements when necessary.
In addition to mulching, other maintenance practices help save water in the landscape. Mowing turf grass at the proper height helps conserve moisture. For example, the optimum height to mow St. Augustine grass for water conservation is three inches. The typical mowing height it two to two and one-half inches. However, the taller height promotes a deeper, more water efficient root system. Taller grass acts like a living mulch, shading the ground, thus reducing moisture evaporation from the soil. Also grass that is allowed to grow taller grows slower; therefore, needing less water and mowing. Another maintenance practice that adds to the efficient use of water by plants is proper fertilization. Applying fertilizer to the lawn at the proper time and in the proper amount can save time, effort and money through reduced mowing and watering. Fertilizers can also be a major source of pollution of streams and groundwater is excessive amounts are applied.
Fertilize the lawn once in spring and again in fall to produce a beautiful turf without excess growth which demands frequent watering. Use a slow-release form of nitrogen in spring and a quick release form in fall. Apply one pound of actual nitrogen fertilizer per 1,000 square feet of lawn at one time. By using this fertilizer schedule, no other fertilizer is needed for most shrubs and trees in the lawn area. Other cultural practices that add to the efficient use of water by plants are periodic checks of the irrigation system, properly-timed insect and disease control and elimination of water-demanding weeds.
