Centipedegrass is subject to a condition called “centipedegrass decline,” which is the failure to green up followed by decline or death in late spring and summer. Many factors may contribute to this problem. It is important to be aware of these factors so that preventive and/or corrective steps can be taken. This problem can be prevented by proper management, which includes avoiding over-fertilization, preventing thatch accumulation, irrigating during drought stress and maintaining a mowing height of 1 to 1.5 inches.
A soil test is always a good place to begin, especially if the grass is showing signs of yellowing as it greened up in the spring, or when it went into dormancy. A routine soil test report includes information on soil fertility and the pH. This report will let us know if the cause is due to pH or nutrient imbalance. Centipede likes a pH of 5.0-6.0, and as the pH goes above the 6.0 mark, iron availability decreases. Iron deficiency causes the grass to become chlorotic or yellow.
In the previous season, was the grass dark green? Centipedegrass is normally olive green in color. If the centipede is dark green for most of the growing season, this means there is an excess amount of nitrogen. This is usually the primary reason for centipedegrass decline.
If the grass can be lifted easily from the soil surface by pulling on the stolons, this is a sign of poor root system development. This can be caused by excess thatch, compaction of the soil or drought stress. Overwatering can also cause the roots to remain toward the soil surface, causing winter kill. Centipede needs about an inch of water per week. Having a rain gauge is recommended. The best time to water is early morning.
Are there any insects (mole crickets) or vertebrates (moles) that can be found in the grass? The presence of these creatures also can lead to decline. If the grass is dying in the spring and summer in a semi-circle, this could be caused by fairy ring fungi. Circular patches may be the result of brown patch fungal infections.
The most important factor for soil health is soil sample analysis; cleaning, grading and tilling the site; and preparing the topsoil correctly for planting by adding needed nutrients (based on the soil analysis) and amending the soil with organic matter. This will permit better root development and a more sustainable lawn.
It is not uncommon for centipedegrass to be over-fertilized. One pound of nitrogen per 1,000 square feet per year is ample nitrogen for most established centipedegrass lawns. Proper fertilization should be based on the soil sample report. Centipede should be fertilized twice per year and not before May. The absolute latest that fertilizer should be put out in the year is August to allow the centipede to prep for winter. The recommended mowing height for centipedegrass is 1.0 to 1.5 inches.
Everyone is getting spring fever to work in their yards, but proper management of your lawn can lead to years of success.
Source: UGA Publications, “Centipede Decline,” Alfredo Martinez
For more information on any program area, contact Houston County Extension at 478-987-2028 or drop by our office in the old courthouse, downtown Perry, 801 Main St. Office hours are 8 a.m.-5 p.m., Monday through Friday. Visit our website at www.caes.uga.edu/extension/houston for more news about your local Extension office.
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DATES TO REMEMBER
April 16: Edible Landscape Class 6-8 p.m., Perry
April 21: 4-H Banquet