Fertilizing Lawns

Everybody wants a lush, green and healthy lawn. Not only is a healthy lawn nice to look at, it is also better able to resist weeds, insects and other stresses. Lawns help cool the environment and provide a place for kids and pets to play. Proper lawn maintenance keeps a lawn looking good. With the arrival of spring, homeowners are ready to apply lawn fertilizer, but how much is appropriate?

Nitrogen is the most important lawn nutrient. It keeps a lawn green and promotes growth. Lack of nitrogen causes slow growth, narrow grass blades and a light yellow-green color. Too much nitrogen at this time of year can cause grass to grow too quickly, before roots can grow. This makes the lawn less tolerant of summer heat. If you applied fertilizer in the fall, you don’t need to fertilize until May.

If you didn’t fertilize in the fall, apply a lawn fertilizer high in nitrogen (21-0-0, 34-0-0, etc.) at about half of what the fertilizer bag recommends. If the first number on the fertilizer bag (nitrogen) is 18 to 21, apply 2.5 pounds of fertilizer per 1,000 square feet. If the number is 24 to 28, apply 1.75 pounds of fertilizer per 1,000 square feet. If the number is 30 to 34, apply 1.5 pounds per 1,000 square feet and if the number is 45 to 46, apply 1 pound per 1,000 square feet (Utah State University Extension).

Most commercial lawn fertilizers will state the proper spreader setting for various rates of application. Water the lawn prior a day or two prior to fertilizing. Apply fertilizer only when the grass blades are dry, unless instructions on the bag state otherwise. Travel in two directions—at right angles to each other—when applying fertilizer. This is particularly true with drop-type spreaders. The cyclone or rotary type spreader applies the fertilizer more rapidly and uniformly with less streaking. Be sure to water the fertilizer in well after application.

Fertilize now at the reduced rate and again in late May at the full rate. Don’t fertilize in the heat of summer, because the cool-season turf grasses used in northern Nevada such as Kentucky bluegrass or turf-type tall fescue should stop growing when temperatures are high or they become more susceptible to disease and insect damage. Wait until September or October for the last fertilization of the season to provide quick green-up in spring.