Different varieties of grass have different fertilization needs. The type of grass in your lawn will determine when to fertilize, what type of fertilizer you will use, and how much fertilizer you will need.
Warm season grasses such as Bermuda, Zoysia, Centipede, and St. Augustine need three to four pounds of nitrogen per 1,000 square feet per year. If you’re going to use a slow-release, high nitrogen formula, you will need to apply it every 90 to 120 days at the beginning of spring, summer, and fall. If you are going to use an all-purpose fertilizer, you will want to put it down every six to eight weeks, as these fertilizers contain less nitrogen.
Cool season grasses such as Fescue, Kentucky Bluegrass, and Rye need one to two pounds of nitrogen per 1,000 square feet per year. This is because they grow and spread more slowly. Also, cool season grasses tend to be semi-dormant in the summertime so you can typically get away with fertilizing in just the spring and fall.
Overall, the best time to fertilize your lawn is the fall, just before or after Labor Day. At this time the lawn is still growing and storing away essential elements and nutrients. The cool weather in combination with the warm soil, sunshine, and ample rain create an ideal environment in which the roots can develop and become hardy.
The second best time to fertilize your lawn is spring, as soon as the dormant grass is fifty percent green again. Use a quick release weed and feed fertilizer to get rid of weeds without harming your grass. This type of fertilizer has a broad-spectrum herbicide in it, but make sure to apply this to damp or wet lawns so the herbicide has quick and easy contact to the weeds. However, avoid using weed and feed on your lawn if you plan to over seed your lawn in the same season.
Summer can be tough on lawns. Adding an application of slow-release fertilizer at the beginning of the season can help combat drought, excess traffic, and even pests if the fertilizer you use includes an insecticide. However, if you have a cool season grass, you may want to avoid fertilizing at this time as the grass is semi-dormant and you will end up feeding more weeds than grass.
With these general rules and tips for fertilizing you will have a yard that is the envy of the neighborhood in no time.