Centipede grass (Eremochloa ophiuroides), a light green warm-season turf grass, grows in U.S. Department of Agriculture plant hardiness zones 7 through 10. It prefers a soil pH between 4.5 and 6.5, and spreads by above-ground runners. It does not tolerate high nitrogen levels, so if you're growing this grass in your yard, fertilize with 1 to 3 pounds of nitrogen per 1,000 square feet of lawn, divided into one to three applications between spring green-up and fall. Mow every seven to 14 days to 1 1/2 to 2 1/2 inches, and irrigate into the top 8 inches of soil when the leaves begin to fold. Improper cultural practices can make centipede grass susceptible to insects and diseases.
Ground pearls are scale insect nymphs that get their name from their yellowish-purple shells. The nymphs emerge in centipede grass during the summer and develop shells as they feed on turf-grass roots. Yellow patches in the grass turn brown and die in the fall. Each ground pearl measures 0.02 to 0.07 inch and turns into a wingless female during the winter and spring. Pesticides do not control ground pearls, states the North Carolina State University Integrated Pest Management Program. Proper watering and fertilizing helps prevent infestation, but you may want to plant a more resistant grass such as Bahiagrass (Papsalum notatum), which grows in USDA plant hardiness zones 7 through 11.
Many types of insect larvae, including white grubs and sod webworms, feed on centipede grass. Destructive white grubs are scarab beetle larvae that spend the winter in tunnels 4 to 8 inches deep under centipede grass. They measure 1/4 to 3 inches long and feed on the grass as they emerge in the spring. Sod webworms live in tunnels during the day and feed at night, and produce fine webs in the grass blades. At the first sign of grubs or sod webworms, spread trichloron granules at 2 pounds per 1,000 square feet of lawn space. Irrigate within 24 hours of application, and do not allow children and pets near treated areas.
Centipede Grass Decline
Brown patch, fairy ring and other diseases contribute to the discoloration and thinning known as centipede grass decline. Brown patch disease causes brown circular patches in humid, moist conditions from spring through fall. To control this disease, irrigate early in the morning to allow the leaf blades to dry, and do not apply nitrogen fertilizer to affected lawns. Fairy ring, a fungus disease, causes rings of dead grass that range from 3 to 20 feet wide. You may notice mushrooms or puffballs near the edges of the rings. To prevent fairy ring in your lawn, remove potential mushroom hosts such as tree stumps and piles of lumber.
Other insects that affect centipede grass include wingless chinch bug nymphs, which measure less than 1/3 inch long and have black and reddish or yellow abdomens. They cause brown patches in the lawn as they feed on leaves in the summer. Trichloron granules spread at 1 1/3 pounds per 1,000 square feet help control chinch bugs when applied at the first sign of infestation. Nutrient deficiencies may cause symptoms that look like disease symptoms. For example, iron deficiency can cause centipede grass to turn yellow. To correct iron deficiency, apply 2 ounces of ferrous sulfate diluted in 3 to 5 gallons of water per 1,000 square feet, recommends the University of Florida IFAS Extension.