Fertilizing a lawn is one of the adventures of home ownership. Lawn grass is not native, and mowing it repeatedly depletes the grass' nutrients. Consequently, it's necessary to add nutrients to the soil, but knowing when and how to apply them is crucial. For the best results, customize your fertilizer application to your lawn.
Conduct a soil test with a kit from a home improvement center, or have your local university agricultural extension do the test. The advantage of "ag" extension tests is that they often come back with specific recommendations for your soil.
Follow recommendations based on soil tests. Purchase fertilizer with the appropriate balance of nitrogen, phosphorus and potassium (N-P-K) for your lawn.
Apply fertilizer in the spring or late fall when it will support rapidly-growing roots and grass plants. Begin early in the morning while the dew is still on the grass. If rain has been scarce, water the lawn to a depth of 1 inch before beginning.
Calibrate your applicator accurately; fertilizer bags usually give a rate of usage in pounds per thousand square feet, but applicators have dials with numbers. Mark off a test strip along the longest side of the yard and weigh 1 lb. of product to put in the bin. Run the spreader along the strip until the product runs out, and use this rate to project the coverage to a thousand square feet. Adjust the dial to increase or decrease the application rate.
Load the fertilizer in the hopper and begin walking. Open the hopper by squeezing the trigger or opening a lever. Walk at a consistent rate back and forth, turning the hopper off for turns and stops. Carefully match the current strip next to the previous one to avoid leaving un-fertilized "stripes." Follow local "ag" extension recommendations for the number of fertilizer applications per season.