How Often Should You Water a Lawn With a Sprinkler System & How Long?

Site Conditions

• Understanding the water needs of your lawn depends on several factors: daily temperatures, soil textures, precipitation amounts, species of grass and amount of sunlight. All of these details can be difficult for the average homeowner to track. Customized water schedules can be obtained through certified water auditors, but unless they are subsidized by local water providers, they can be expensive. It's easy to know when to water without hiring someone, though. Simply observe the amount of moisture in the soil and the condition of your lawn.

Soil Moisture

• To determine the amount of moisture existing in your soil, insert a screwdriver or similar instrument into the soil. If it is easily pushed several inches in, the soil has enough moisture. If the screwdriver only goes in an inch or less, the soil is most likely dry. Soil texture affects the amount of moisture your soil can hold. Clay soils hold the most water but don't absorb water quickly. The opposite is true for sandy soils. Knowing the soil texture in your landscape will also provide clues as to how soon it will dry out.

Lawn Water Stress

• Observing the condition of your lawn is another easy way to know if it's time to water. A lawn that needs water will slightly wilt and turn a darker hue. When stepped on, wilting lawns will not immediately spring back. Although these changes can be alarming, lawns will handle some water stress without any permanent damage. In fact, allowing a lawn to show signs of need before giving it water will help the roots grow deeper.

Irrigation Timing

• Once it's time to water your lawn, it's best to apply a consistent amount of water each time. In general, 1/2 inch of water is the most a soil can hold. You can use a tuna can or other shallow container to find out how long to run your sprinkler system. Mark the 1/2-inch depth in your container, place it on your lawn, and run your system. Record the amount of time it takes to reach 1/2 inch. That's the approximate amount of time you should run your system. Instead of changing the run time with the season, vary the frequency of irrigation sessions, allowing a longer period to elapse in the spring and fall and shorter in summer.