Proper Watering
Water deeply but infrequently - Daily watering can actually hurt your grass
Grasses do better when the whole root zone is wetted and then partially dries out between waterings. Avoid frequent shallow watering; that causes shallow rooting. Overwatering can promote lawn disease, leach nutrients from the soil, and waste water. Newly planted lawns will need daily watering if planted in the late spring or summer. Replant in September to avoid that chore, but be ready to water if it stops raining.
Click on this link to download the guide to Smart Watering, (pdf, 505 KB.)
Aeration helps water reach the roots
Aerate the lawn if water won't penetrate because of soil compaction or thatch buildup. Dethatching will also help if there is heavy thatch buildup.
One inch per week, early or late in the day
Water about one inch per week during July and August. Use less in late spring or early fall-let the weather be your guide. Water slowly, or start and stop, so the water penetrates rather than puddling or running off. Sandy soils will need lighter, more frequent watering because they can't hold much water. Water early or late, not in the heat of the day.
Dormant lawns will recover in the fall
Consider letting the lawn go brown and dormant in the summer. Watering deeply but slowly, so it penetrates, once each rainless month will help support dormant lawns so they recover better in the fall. (Perennial ryegrass lawns on sandy soil will not survive if allowed to dry out completely.) Avoid heavy traffic on dormant lawns, or regularly water the play/high use areas to prevent damage. When rain returns in the fall, overseed any thin areas to thicken the lawn and help crowd out weeds.
Watch the weather (don't water if it's going to rain). Signs of a lawn that needs more water include a duller color, and the "footprint test": grass blades stay bent in your footprint rather than popping back up. Or call your water utility for information on how to use evapotranspiration (ET) rates to match your irrigation to current weather conditions.