Lawn fertilizers should be applied according to the specific climate, location, and species of grass in your yard.
As a general rule of thumb, lawn fertilizers are best applied throughout the year, with the most important applications being in spring and fall. The milder times of the year, when the weather is not too hot or not too cold are best. May and June or early spring, and September and October or early fall, provide for efficient application and avoid the hot summer sun and freezing winters.
Why is it important to avoid extreme temperatures? If it’s too hot, the chemicals can actually burn your lawn. And if it’s too cold, your lawn has likely already gone dormant and won’t soak up the nutrients provided in the fertilization products.