Thomas J. Koske | 4/20/2006 11:52:42 PM
Spring has sprung, and the grass is now growing. But, says LSU AgCenter horticulturist Dr. Tom Koske, there is usually no good reason to push early growth with lots of fertilizer.
The horticulturist says that’s because our warm-season permanent grasses are waiting for the days to get really warm. Once soils have consistently held a temperature in the high 60s at 2-inch depth, good dependable growth is assured, and the grass will definitely need some lawn food.
"Wait until the lawn greens up enough to warrant a second mowing before starting the season's fertilizer program," Koske advises, explaining, "At that time, fertilize according to soil test results for best stewardship of the turf."
Without test results, you can only assume an average residual of soil nutrients and acceptable soil pH. As such, you would not lime and would choose an average turf-blend fertilizer. This is a blend with high nitrogen, low phosphorus and medium levels of potassium. Apply this so that you administer about 1 pound of nitrogen per 1,000 sq. ft. If you have centipede, carpet or zoysia grasses, use about half that rate. This should carry you for about two months.
Mow regularly with a sharp blade whenever the grass grows back 50 percent more than the height after cutting. Mow St. Augustinegrass at 2 ½ to 3 ½ inches tall while keeping centipede around 1 to 2 inches.
Water only as needed. There are many weeks when no irrigation is needed, no matter how much you paid for that irrigation system. Overwatering can bring on extra disease and a short root system that makes the turf more fragile.
"Now is the time to control weeds with a post-emerge spray program," Kokse advises, urging homeowners to control weeds before it gets too hot to do so without turf injury.
"April and May are peak weeding months, so don’t miss this window," the horticulturist says, noting, "By July, it's too hot for most weed control materials."
The LSU AgCenter and the LSU College of Agriculture