Water when the lawn needs watering. The lawn has a way of letting you know when it is in drought trouble. If you stand back and see a purple tint to the lawn, it is heading for trouble. Start watering right then--it will take less water at that point to keep it healthy. The next step the lawn will take without watering is dormancy (brown). When that happens, it takes a lot of water and time to get the lawn come out of dormancy and grow back green again.
How much and how often to water. With an irrigation system, watering daily for 15-30 minutes will generally keep the lawn in good condition (except for extreme drought years). Since watering with a sprinkler is not as efficient, it is often a good idea to water each area for 30-60 minutes every three days to give the lawn a deeper, more even watering. Remember, a five minute rain shower is NOT considered a good watering.

When to water. The best time to water is in the morning. Then the lawn may be damp from dew, and your watering will add to that and penetrate the soil more easily. Watering during the heat of the day is NOT a bad thing--it cools the lawn and gives it a break from the heat. Watering close to sunset or after IS bad. This will send the lawn into the night wet, and dew will add moisture--all of which increases the chance for disease in your lawn. The lawn should have an opportunity to dry before nightfall.

What to expect from watering. Remember that watering will not always keep the lawn green. Sometimes watering seems futile--the lawn stays brown. There may be another problem in the lawn--insects or disease. However, if the lawn is simply in drought stress, watering will bring it back more quickly when the cooler, damper season arrives.