Fertilizer provides moderation of soil temperature, increased moisture retention and provides vital minerals and nutrients to the topsoil. Proper fertilizer applications will enhance the health of the turfgrass and reduce the risk of toxic topsoil and weed infestation. Before purchasing lawn fertilizer, test your topsoil and determine your lawn's area.
In the late fall or winter have your soil tested to determine the best type of fertilizer to apply on your lawn in the spring and summer. Most states provide free soil testing through the Department of Agriculture or state university programs. Take several soil samples from your lawn at a depth of 4 to 6 inches. Send the soil samples in for analysis following the recommended procedures for your state.
Amount of Fertilizer
Before purchasing any fertilizer, determine the area of the lawn you intend to fertilize. Lawns often have irregular shapes that are challenging to measure. The simplest way is to divide the lawn into smaller squares and rectangles and then take the sum of all the areas. Plan to purchase 1 lb. of fertilizer for each 1000 sq. ft. of surface area.
Choosing the Fertilizer
Based on the results of your soil test, choose the type of fertilizer that is best for your lawn. Fertilizers are labeled based on their percentage of Nitrogen, Phosphorus and Potassium. The soil analysis will indicate any deficiencies of these vital topsoil elements. Select a fertilizer that compensates for your lawn's deficient elements to maximize the effectiveness of the fertilizer applications.
Fertilizer is best applied using a spreader that evenly distributes the fertilizer 3 to 5 feet either side of the spreader as you walk over the lawn. Overlap the fertilizer applications such that each successive pass throws fertilizer over the wheel tracks of the previous pass. Do not apply fertilizer immediately before or after a heavy rainfall. Sweep fertilizer off driveways, walkways and other unwanted areas after applying fertilizer on the lawn. Excessive fertilizer is food for weeds.