Watering the Lawn

Improper irrigation of lawns results in waste, added cost, and unhealthy plants. Water should be applied only when lawns show signs of moisture stress. A dark bluish gray color; footprints that remain some time after walking; and wilted, folded, or curled leaves are indications that it is time to water. 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 to water because it reduces the risk of disease, water loss through evaporation, and improper water distribution. You can water at night if it is not done on a frequent basis. Wet foliage for extended periods of time can cause disease problems.

Established lawns should be watered to a depth of 6 to 8 inches to encourage deep rooting. Usually, 1 inch of water per week is adequate. 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. Clay soils accept water slowly; water until runoff is about to occur. Wait 30 minutes for the water to be absorbed, then rewater until the desired depth or amount is achieved. This same technique can be used on slopes and compacted soils. Few lawns on clay soils can absorb more than 1/2 inch of water per hour.

Sandy soils require more frequent watering; applying 1/2 inch of water every third day. Adjust any automatic irrigation system to supplement rainfall so that the lawn is not overwatered.

Certain precautions should be taken if you do not plan to irrigate throughout the summer. Slowly ease a lush, actively growing lawn into dormancy. This can be accomplished by deep and infrequent watering, by mowing high, and by not overfertilizing with nitrogen. In the absence of rain, water dormant lawns every 3 weeks to prevent turf loss from heat and drying. Brown, withered leaves are normal signs of dormancy; don’t be alarmed by them. Turfgrasses are able to withstand prolonged periods of drought. Do not regularly water cool season grasses during the summer unless you plan to do so all season. Many lawns are lost by discontinuing irrigation in midsummer.

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