Fertilize a lawn every six to eight weeks during its growing season. Each type of lawn has a different active season. There are two types of lawns, those with warm-season grasses and those with cool-season grasses. Ask a landscaper to determine which type of grass is in the lawn, and fertilize accordingly.
Warm season grasses grow mostly during warm weather. These grasses include St. Augustine and Bermuda grass. Cool-season grasses grow mostly in the fall and spring. However, the southern states can see these types of grasses grow during the winter. Cool-season grasses include Kentucky bluegrass and tall fescue.
The more effectively a lawn is fertilized, the more often it requires mowing. If there is a desire for less-frequent mowing, fertilize warm-season grasses once in the early summer and once in the latter portions of summer. Fertilize cool-season grasses once in the spring and then once in the fall season. However, fertilizing can happen once per year in the fall for cool-season lawns or once in the late spring for warm-season lawns. No matter how often fertilizing takes place, make sure that the nitrogen per square feet level is appropriate for the type of fertilizer and the type of lawn.