Choose a fertilizer that contains a high percentage of controlled-released nitrogen. If you only feed your lawn once a year, do so in the late fall for maximum benefit. Use a fertilizer that feeds both the soil and the grass. Nitrogen promotes the deep rich color in a lawn by stimulating leaf development. Phosphorus feeds the roots and transfer systems in the plant.
Potassium helps the plant withstand stress, disease and insect damage.
Yet these ingredients alone will not guarantee a healthy lawn. Your grass is only as good as the soil in which is lives. Humus is the rich top soil. It is made up of dead and decaying plant stems, roots, and leaves and microorganisms. The microorganisms break down the decaying plant material, which feeds the grass plants.