By Brad Haire
University of Georgia
An inch of water a week is the rule of thumb.
Most sprinkler systems apply about one-fourth inch of water per hour. But sprinklers can vary. They all have different nozzles, so test your system's output.
To test sprinklers, place open-top containers of the same size, such as margarine tubs, randomly on your lawn. After an hour, measure the amount of water in each container.
The difference in the amounts will give you an estimate of the water distribution and application rate. When you have an inch of water in your containers, you know you've applied enough water.
Keep in mind the rate at which the soil absorbs water, too. Apply enough water to soak the soil 6 to 8 inches deep. If your system is applying water too fast, you're just watering the curb and sidewalk, because the water is running off.
To make the most of your efforts, water between sundown and sunrise.
If your street address is an odd number, you’re asked to water on Sunday, Tuesday and Thursday. If it is an even number, you’re asked to do it on Monday, Wednesday and Saturday. There’s should be no outside watering done on Friday.
Watering turf more often than recommended will actually hurt it. Light, frequent irrigation produces shallow and weak root systems. A shallow root system prevents efficient use of plant nutrients and water in the soil.
Mowing your lawn regularly is important, too, especially during dry spells. Mow often enough that you remove no more than one- third of the leaf tissue during a cutting. And raise the mowing height. This helps the grass maintain a deep root system, which helps it find more water.
