At the first sign of green grass in the spring, it is tempting to dust off the fertilizer spreader and apply nitrogen to the lawn. If you applied nitrogen late last fall or winter, there's no need to apply nitrogen this spring because the lawn already should be starting to green up.
Applying nitrogen now also will make grass less heat and drought tolerant and cause more problems with weeds and diseases. Weeds compete with grass for moisture and nutrients.
But if you did not fertilize the lawn last fall, applying nitrogen this spring will be beneficial because it will green the lawn and make it look better for a few weeks.
However, spring fertilization causes such fast top growth you have to mow every four to five days in April and May to remove only one-third to one-half of the grass leaves each time. Cutting several inches of top growth at one time creates excess clippings that smother the grass below, or must be bagged and added to landfill debris.