An established lawn is one that has been mowed three times. Irrigating Improper irrigation of lawns results in waste, added cost, and unhealthy plants. Overwatering can cause fertilizers and pesticides to penetrate below the root zone where they may enter groundwater. Water should be applied only when lawns show signs of moisture stress. Delay in watering at first signs of wilt can result in permanent damage unless the turf is being allowed to go dormant.
Early morning is the preferred time for watering.
If you must water in the evening, allow sufficient time for the leaves to dry before nightfall to lessen the chance of disease. Avoid midafternoon watering to reduce loss from evaporation. Established lawns should receive sufficient water to moisten soil at a depth of 4 to 6 inches to encourage deep rooting. Cans or a rain gauge can be used to determine how much water is being delivered in a certain period of time. It takes 640 gallons of water to apply 1 inch of water per 1,000 square feet.