Centipede Lawn Problems
Written by: Charlotte Glen, Horticulture Agent
In some yards centipede grass thrives on neglect, producing a dense, healthy, carpet of grass with little care. In others centipede lawns are plagued with problems. Some of these are caused by insects or diseases, while others are due to incorrect care. Figuring out which problem is the cause of your centipede lawn’s decline relies on careful consideration of the symptoms and how the lawn has been treated.
What Centipede Likes
Centipede grass prefers to grow in well drained, acidic soil in full sun. The target pH for centipede grass is 5.5. When grown on soil with a pH over 6.5, centipede may appear yellow due to iron deficiency, especially in spring as the lawn greens up. Many soils in our area near the coast have pH levels much higher than 5.5. If you are trying to grow centipede and it is struggling, you should have your soil tested to determine the pH level. Soil testing is free. Bring samples to your local Extension office to be sent off for analysis.
Mowing at the correct height is an important part of centipede care. To keep centipede lawns healthy, mow low, around 1” and no higher than 1.5”. Centipede lawns that are mown high are more prone to cold damage than those that are mown lower.
Centipede lawns require little fertilization, especially in heavy or clay soils. Even in sandy soils only one application of fertilizer is usually needed. To fertilize centipede lawns, apply 5-0-15 fertilizer at a rate of 10 pounds per 1000 square feet. The best time to fertilize centipede is late April or early May. Applying too much nitrogen can increase disease problems in centipede and cause thatch build up. Fertilizing too early increases the risk of cold damage caused by late season frosts.
Centipede is sensitive to some herbicides, especially those that contain 2,4-D. Over applying 2,4-D will cause centipede lawns to weaken and decline. In addition, many herbicides sold as crabgrass preventers reduce centipede grass’s ability to recover from injury. If your lawn has dead or declining areas, do not applying crabgrass preventers. Weed and feed products should also be avoided because they often contain herbicides that are damaging to centipede grass and the time to apply most herbicides is not the correct time to fertilize.
Insects and Diseases
Centipede has a couple of serious pest problems that are common in our area. Large patch is a fungal disease that causes circular patches of grass to turn brown and die. These patches may start out 2’-3’ across in spring but can rapidly expand to cover 10’ or more within a few weeks. This disease subsides in summer and new grass often grows back into affected areas. Large patch is encouraged by over fertilization, fertilizing too early, over watering, poor drainage, and excessive thatch levels. Correcting these problems will reduce disease pressure, though fungicide applications are usually needed to control this disease. Lawn fungicides containing triadimefon or azoxystrobin work best for controlling large patch. These products can be applied in spring, though best results occur from fall applications, even if symptoms are not present. If your lawn has large patch this spring, map out the affected areas and spot treat them this fall.
Ground pearl is a type of insect that lives in the soil and severely damages most grasses. Areas infected with ground pearl turn yellow, then brown, and die. No grass will grow back into affected areas. The small round, tan colored ground pearls can be found in the soil at the edge of dying areas. Areas infected by ground pearl get larger slowly, growing about 1’ in diameter each year. While ground pearl will feed on all types of warm season turf grasses, centipede is damaged most severely because of its low vigor. There is no way to treat ground pearl, though zoysia grass, tolerates its feeding better. In most cases where ground pearl are a problem it is not possible to grow centipede grass. Trees, shrubs and perennials are not bothered by ground pearl and can be planted in infested areas.
For more lawn care advice, visit Cooperative Extension’s TurfFiles website: http://www.turffiles.ncsu.edu/, where you can download the free lawn care app and receive the regular updates on your smart phone about what, how, and when to care for your yard.
Find out what you need to do to keep your centipede lawn healthy year round – download the Centipede Lawn Maintenance Calendar: http://www.turffiles.ncsu.edu/Maintenance_Calendars.aspx#000019
Learn more about ground pearl from the Pender Gardener article: http://pender.ces.ncsu.edu/index.php?page=news&ci=LAWN+133
Learn more about controlling Large Patch from this Extension fact sheet: http://www.turffiles.ncsu.edu/Diseases/Large_Patch.aspx
Not sure what is wrong with your lawn? Bring a sample to your local Extension office for identification. In Pender County, call 259-1235, visit our office in Burgaw, or visit us online anytime and post your questions and pictures using our ‘Ask an Expert’ widget, http://pender.ces.ncsu.edu/index.php?page=askanexpert.
Visit the Pender Gardener Blog to stay up to date on all the latest gardening news, http://pendergardener.blogspot.com.