September is here, and it is time to think about fall fertilizers for lawns. Sometime around the end of September, the evening temperatures cool down to 50 degrees or below. That is the time to get out the spreader! Another great indicator that it is time to fertilize your lawn is when you do not need to mow for two weeks or so. It is important to fertilize the lawn in the fall to prolong fall color and increase winter hardiness. Also proper fertilizer helps maintain a dense turf that resists winter weeds.
Our alkaline soils have lots of their own phosphorous, so Texas A&M suggests fall fertilizers should be high in nitrogen (the first number) and very low in phosphorous (the last or third number). Usually the amount to be applied is one pound of nitrogen per 1,000 square feet of lawn. Most bags of fertilizer will tell you how much the bag will cover. Organic or chemical makes no difference as long as the numbers are the same.
Watering the lawn is the icing on the cake because it activates the fertilizer. Spray and soak will give you the best results, with the fertilizer going to the roots rather than running into our streams and lakes. This consists of several short periods of watering (the lawn, of course, not the street or drive) relatively close together, so the water soaks into the ground, rather than one long period when it runs off.
If you have more questions about lawns, call the Texas AgriLife Extension at (972) 825-5175.
Written by Nancy Fenton, Master Gardener.