When Should You Put Down Lawn Fertilizer?

Absolutely nothing is more critical for raising a healthy, thick and green turf than fertilizing. Providing your grass with the right level of nutrients ensures thick growth that retards weed invasions and also resists diseases. But it's not just about how much fertilizer you use -- which varies depending on the specific fertilizer product. It's also important to provide the fertilizer at the right time.

Your future turf will require high levels of nutrients, and preparing the soil bed with fertilizer before you plant your grass ensures a healthy, vigorous start. After tilling the soil to break up dirt clods, spread any standard lawn-starter fertilizer at a rate that gives the soil 1/2 lb. per 500 square feet of lawn space. The guidelines vary depending on the individual nitrogen ratios of the fertilizer, which differs between products. The fertilizer will have the specific application rate listed on its label.

After you've either laid your sod or germinated your grass seeds, wait until the new grass is approximately 1-1/2 inches tall. This may take three to four weeks. At this point, apply standard lawn fertilizer again at a rate of 8 oz. of nitrogen for every 500 square feet of growing grass.

Once your grass has become established, settle into a standard annual fertilization schedule. This schedule launched in the late spring, such as mid- to late-April, once your yard has thawed and is no longer frozen. A dose of fertilizer helps bring the grass out of its winter dormancy. Use any general lawn fertilizer, such as 10-6-4 or 29-3-5, according to its labeled guidelines. If you struggle with invading weeds such as nut grass -- weeds often arise during the spring when the turf is still thin and weak -- use fertilizer that's enhanced with pre-emergent herbicide. This kills any weed seeds without affecting the already established grass plants.

After the spring fertilization, continue fertilizing with standard lawn fertilizer every eight to 10 weeks. Thus, you'll be fertilizing again in June or July, August or September and finally in October or November. Such regular fertilization ensures that your grass has the nutrients it needs during the summer growing season, which is simultaneously the time that it grows the most and also encounters the most environmental stress due to summer heat and regular mowing.

When you mow your grass, don't remove the clippings. Instead, let them lie on the surface of your turf. This alone works as an act of regular, moderate fertilization. The decomposing clippings return a whopping 25 percent of your lawn's fertilizer nutrients back to the soil, and also helps enhance the level of friendly bacteria in your lawn soil. By carting off your lawn clippings like many homeowners do, you rob your grass of important micronutrients.