We face a tough dilemma during a hot, dry summer like this in Central Texas. The plants in our lawns and gardens need water to survive and thrive, but we know that water is a limited resource. My budget is a limited resource, too, which keeps my watering habits in check when I reach to turn on the sprinkler! With this dilemma of plant health and water conservation in mind, there are a few things to know about turfgrass to help you manage your lawn through the drought this summer.
In Central Texas, we grow warm-season grasses in our lawns like Bermuda, St. Augustine, and Zoysia. These grasses like full sun and can tolerate our hot summers. Each of these grasses have some plant characteristics that help them to survive drought like developing deep root systems, a high tolerance to tissue dehydration, or reduced leaf area.
We can manage our watering schedule to work with these characteristics. Water deeply and infrequently to encourage deep root growth. During dry times, the roots will be able to access water that is deeper in the soil. Rolled leaf blades and wilt are the physiological signs that the plant needs water. Wait until you see visual signs of wilt to water your lawn.
During dry times, plants slow down their growth, and they do not need as much fertilizer. Nitrogen encourages shoot growth and water use in plants. Use low levels of fertilizer or stop fertilizing for a few months in the hottest part of the summer. The added benefit is that you will not have to mow very often!
When you do pull out the lawn mower, use the highest setting for your type of grass. Taller grass will shade the surface of the soil, which keeps it cooler and prevents water from evaporating as much. The taller shoots will also promote deeper root growth and drought survival. The highest recommended mowing height for St. Augustine is four inches; Bermuda is three inches; and Zoysia is two inches.
Be sure to check your city water department for current watering guidelines. Remember, just because the water department says you are allowed to water your lawn two times per week, that does not mean you have to water! If you have deep soil, try to water one time per week to encourage deep rooting. You might need to split your water applications into two days if you have shallow, rocky soil because it dries out faster. Shady areas underneath trees and beside buildings will not require as much water.
For more information about lawncare or water use, contact Kate Whitney, Williamson County Extension Agent for Horticulture, at 512-943-3300.
