The answer to 'frequency of lawn fertilization' is that most lawns should be fertilized 2-4 times per year. The optimal times are typically in the early spring, late spring, late summer, and/or early fall. Fertilizing your lawn on a regular schedule helps promote healthy, green grass by providing essential nutrients.
The specific number of times you should fertilize will depend on factors like your grass type, climate, and lawn usage. Cool-season grasses like fescue or bluegrass usually need more frequent fertilization, around 3-4 times per year. Warm-season grasses like bermuda or zoysia may only need 2-3 applications annually. It's best to follow the recommendations for your local climate and grass variety to keep your lawn looking its best.