Spring, warmer weather and the growing season are upon us. It's time for us do-it-yourselfers to start thinking about the lawn. If we have taken care of the lawn properly, we should be weed free with a lush stand of our favorite grass variety from bermuda to centipede. So, we run down to our favorite store and grab a bag of 10-10-10 and spread the whole bag out over the yard. That might work for a while, but you are probably wasting money, water resources, time and effort. A properly fertilized turf grass in the right soil conditions can be fed more precisely with a soil analysis thus saving money, maintenance, time and effort, and simultaneously conserving irrigation water.
A soil test can yield information such as the soil pH, the nutrient availability in the soil, the micronutrient levels, and if there are any salinity or sodium problems in the soil. With these facts we can then determine the best ratio and amount of fertilizer to apply to yield a healthy turf grass.
The three major components added to the soil via commercial fertilizer are (1) nitrogen (2) phosphorus (3) potassium. On every bag of fertilizer, by law, is an analysis of the contents expressed in the amount of nitrogen, phosphorus, and potassium; i.e., 20-10-5 indicates 20% nitrogen, 10% phosphorus, and 5% potassium. A fifty pound bag of 20-10-5 analysis fertilizer will yield 10 pounds of nitrogen, 5 pounds of phosphorus, and 2.5 pounds of potassium. The remaining 32.5 pounds in the bag is filler. You can adjust the analysis and the amount of application to follow the guidelines provided by the soil test.
You should develop a personal fertilization program for your turf based on soil test analysis, turf grass requirements and mowing/maintenance program. An under-fertilized lawn will have a thin, poor colored turf while lawns that are over-fertilized may develop thatch and be subject to disease, insects, and damage from use.
John Meadows, Smith County Master Gardener
Texas AgriLife Extension Service
Landscape Index
Gardening Tips For NorthEast Texas Index
East Texas Piney Woods Gardening Home Page