Texas Lawn Watering Guide

Did You Know That?

Landscape irrigation can account for more than 30 percent of all the water used during the summer in Texas. Unfortunately, about half of this water is wasted due to over watering.

Soil type, slope of the landscape, water requirements of the turfgrass type, and efficiency of sprinklers all affect how often you need to water.

Turfgrass generally requires more frequent watering than WaterWise plants. That is why it is important to use turfgrass sparingly an in functional areas that can be efficiently watered.

Soil Type

Lawns grown in sandy soil require more frequent watering than lawns in loam or clay soils. Water can be applied less often to clay and loam soils, but it should be applied more slowly to prevent runoff. Soils can be improved by topdressing the lawn with about one-half inch of compost per year. If you are establishing a new lawn, consider blending topsoil with about 25 percent compost. Soil testing offered through the Texas Agricultural Extension Service would enable you to determine the best product for your lawn.


To avoid runoff on sloping areas, place sprinklers near the top of the slope. Apply water slowly for 5 to 15 minutes, off 15 minutes, then on 5 to 15 minutes, etc. until you have applied the correct amount of water. Groundcovers work well in areas that are sloping, narrow, small, odd-shaped, or close to pavement. These areas are hard to water without runoff and overspray.

Trees, Shrubs, & Groundcover

Established plantings do well in the summer when watered about once a week, especially if mulch is placed around plants. Apply emough water to wet the soil to a depth of at least 12 inches. Low output sprinkler heads, bubblers, or drip irrigation systems will decrease runoff and are efficient ways to apply water. New plantings require more frequent watering the first year. Grass and weed removal from beneath trees and shrubs allow their roots to be more evenly distributed, increase in number, and utilize a larger volume of soil. Consider Texas-Grown, WaterWise varieties when purchasing new or replacement plants.


This is a layer of material covering the soil surface around plants. Mulch reduces evaporation of water from the soil, keeps the soil cooler, and limits weed growth. Use mulches wherever possible. Three to four inches of mulch should be maintained around plants and trees. Some examples of mulches are pine bark, pine straw, compost, wood chips, or straw.


Turfgrass takes on a dull, dark appearance and leaves begin to roll when they need water. The best time to water is early morning or late evening when winds are calmer and temperatures are lower resulting in less water loss to evaporation. Water lines tend to have better pressure during these times.

How Much?

Apply enough water to wet the soil to a depth of four to six inches, reaching the plant’s root system. Use a soil probe or screwdriver to determine the depth the water actually reaches. Soil type, amount of rainfall, and season of the year all affect the amount of water you will need to apply. Healthy, properly irrigated turf rarely requires more than one inch of water per week during the summer months. Unless there is an extended dry spell, there is rarely a need to irrigate during the winter.

Application Strategy

Use a sprinkler that emits large drops of water that remain close to the ground, not one that sprays a fine mist into the air. Water deeply and frequently to encourage deep, well established root systems. Water trees, shrubs, and other landscape plants separately from turf.

Determine Application Amount
  • Determine how much water your sprinkler applies:

    • Set three to five empty cans at different distances from the sprinkler with the last can near the edge of the sprinkler coverage.

    • Run the sprinkler for 30 minutes.

    • Measure the amount of water collected in each can in inches.

    • Add together the measurements from each can and divide the total by the number of cans to obtain an average.

    • Multiply the average by 2 to determine how many inches of water are applied in 1 hour.

  • Locate your area on the map to find out how many inches of water to apply every fifth day to bermudagrass during June, July, and August. Buffalograss needs about 25% less water than what is shown, and St. Augustine needs about 15% more.

  • Subtract any rainfall from the amounts given on the map to determine how much water to apply.

  • This test will also locate uneven distribution of the sprinkler system and define wet and dry spots.

For more information, contact your County Agricultural Extension Agent, local WaterWise landscape professional, or Texas WaterWise Council (www.waterwisetexas.org)