Lawns composed mostly of turf-type tall fescue will withstand drought conditions unless they are newly seeded or sodded. Established fescue and bluegrass lawns should not be irrigated. Light, frequent watering is harmful because it encourages shallow rooting. Fescue lawns turn brown and become dormant during a drought, but green up and grow with a return to cooler, wetter weather. (Footprints will remain in drought-stressed turf.) Like fescue, bluegrass is a cool-season grass that will become dormant during droughty weather. Bermudagrass and zoysiagrass are warm-season grasses that cope well with hot, dry weather and require no irrigation. Increasing the mowing height to 3 to 4 inches for cool-season turfgrasses will also help them withstand drought conditions.
Irrigate an established lawn only when needed rather than on a schedule. Water if the grass develops a blue-gray color or if walking on it leaves footprints. Water slowly to allow water penetration and to prevent runoff. Wet the soil to a 4-6 inch depth. You can check the depth with a screwdriver. Early morning (5 am - 8 am) watering allows the grass to dry before night and reduces the chance of disease. Shallow, frequent watering, or watering in the evening, can damage your lawn.