Many lawns can survive drought quite well by going dormant (leaves turn brown), if the turf is healthy and damage from insects, diseases, or foot traffic are minimal. Drought-induced dormancy of lawns in New Jersey is rarely long enough to cause failure of the grass, if the lawn is healthy. Allowing an unhealthy lawn to go dormant on poor soils will result in severe thinning of the lawn. Thinning of the turf enables weeds to invade the lawn when rain re-wets the soil, thus increasing the need for herbicides. In severe cases, thinning of the lawn will result in erosion of exposed soil during rainstorms increasing the likelihood of water quality impacts through sedimentation. Thus, maintaining a healthy turf cover on a lawn enhances both drought resistance and environmental quality.
If a decision is made to stop watering during severe drought, decrease mowing frequency and raise the mowing height (3 inches) as the soil dries and growth of the grass slows. Mowing during the coolest part of the day (early morning) will minimize the added stress caused by mowing. Ultimately, mowing should be stopped when the soil dries to the point that the lawn is wilted. Mowing when the lawn is wilted can damage the lawn. A lawn wilts severely before it becomes dormant.
Excerpted from Rutgers Fact Sheet FS555