Problem: Nitrogen Deficiency
Nitrogen is a key element in maintaining a healthy lawn with few insect and disease problems. Clover stays green because it obtains nitrogen from the air, but grasses cannot. It is best to maintain a level of nitrogen in the soil that (1) does not stimulate excessive leaf growth, which would increase the frequency of mowing, (2) does not encourage shoot growth at the expense of root growth, and (3) varies according to the cultural and environmental conditions present. Because heavy rains and watering leach nitrogen from the soil, periodic feedings are necessary throughout the growing season. Acid soil may cause nitrogen to be unavailable to the grass.
Properly fertilized lawns are dense and have a nice green color without excessive growth. To prevent burning and to move nutrients into the soil, water thoroughly after application. Grass begins using the nitrogen in the fertilizer within 15 to 24 hours. Recycle the nitrogen by leaving grass clippings on the lawn if they are not extremely long.