Fertilize for future growth
Most lawn experts agree: If you fertilize your lawn only once a year, do it in the fall. The reason? Grass leaves grow much more slowly as the weather turns cool, but the grass roots and rhizomes continue to grow quickly. Rhizomes are the horizontal plant stems that lie just beneath the soil’s surface; they produce the blades of grass above and the roots below.
A fall application of fertilizer delivers essential nutrients for the grass to grow deep roots now and to keep nutrients in reserve for a healthy start in the spring.
Wait until mid-to-late fall, then apply a dry lawn fertilizer to all grassy areas; don’t miss any spots. You could use a crank-style broadcast spreader, but for optimum coverage, consider using a walk-behind drop spreader. It takes a little longer, especially on hilly yards, but a drop spreader provides the best way to apply an even, consistent layer of fertilizer.