One pound of nitrogen per 1,000 square feet should be sufficient. Keep mower blades sharp to reduce the area of open wounds through which fungi can enter. Reduce excess thatch accumulation by aerating annually either in spring or fall. Thatch is a layer of slowly decomposing grass stems, dead roots and debris that accumulates above the soil line and below the grass blades. When this layer reaches more than 1 to 2 inches, however, it stops water and fertilizer from reaching the soil.
Turf roots begin to grow in the thatch rather than the soil.
Plants from these roots are less temperature and drought resistant. A thick thatch layer also can enhance the build-up of diseases and insects. Irrigate infrequently but deeply to a six to eight inch depth. This encourages deep root growth. When controlling any type of disease, insect or weed problem, find out what you may or may not be doing to encourage pests.