Overall browning of tall fescue yards is very common in the summer. Most people think if they water the turf a few times here and there it will help the lawn get some color back, but this can actually do more harm than good! An overall brown color in the lawn is a telltale sign that dry/hot conditions have set in and your grass is doing what it needs in order to survive these long stretches without significant rainfall. A quick thunderstorm or a short burst of watering will not provide enough water for the grass to start to bounce back. The turf will wait for slow consistent watering or cooler temperatures before it will return to it’s green and beautiful state once again. Hang in there!
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.
-University of Maryland Extension