Tall fescue and particularly Kentucky bluegrass may need moderate additional applications of fertilizer to maintain density and resist pest problems. Do not forget that practices that keep lawns healthy, like proper mowing, can also reduce the need for fertilizer. If you apply fertilizer in November or late Spring, consider using a slow release nitrogen source. Unless you have bluegrass, it is safe to let an established lawn go dormant during dry periods. Dormancy is a survival mechanism and your lawn will usually recover when rainfall returns.
Dormant lawns continue to protect water quality by holding soil and potential pollutants.
Watering Once you have an established lawn, water only when needed rather than on a schedule. Water if the grass develops a blue-gray color or when it leaves footprints after being walked upon. Water slowly, preferably in the early morning. Wet the soil to a 4-6 inch depth. You can check the depth with a screwdriver.