Yes! There is a right amount of fertilizer to apply and there are a variety of ways to over-fertilize your lawn. You can simply add too much all at once, you can fertilize the right amount too often, or your yard can suffer from fertilizer buildup if the drainage is poor. Devising a fertilizer program is too in-depth to describe in this section. The best way to be sure is to identify the species of grass in your yard and look up how much fertilizer they need and when. Different grasses require fertilizer in different amounts depending on the time of year.