If areas of your centipede lawn failed to green up this spring, you are not alone. Cold weather this past winter damaged lawn grasses in our region, particularly centipede. Large areas of dead grass are a likely sign of cold injury, but cold weather is not the only culprit that could cause these symptoms. Diagnosing the cause of turf damage is the first step in repairing spotty lawns.
Symptoms of cold injury
Lawns injured by cold typically exhibit large areas of dead grass that never turned green this spring. Two symptoms that distinguish damage caused by cold injury rather than insects or disease are: 1) that the damage occurred over the winter — in many cases these lawns appeared healthy and thick last summer and fall but this spring large areas of lawn, sometimes several feet across, never turned green; and 2) the problem is not expanding — the areas that failed to green up this spring are staying the same size, and dead or dying turf is not spreading into healthy, green living grass.
Before you conclude winter weather is the cause of your turf problems, consider the other possible culprits. The most common pest problems that cause damage in centipede grass similar to cold injury are large patch disease, mole crickets, and ground pearl. Large patch, a fungal disease, starts out as small circular areas of dying grass that rapidly expand to cover large circular patches that may be several feet across. With this disease you will see healthy, living green grass yellowing and dying. During the summer, areas damaged by large patch usually recover but symptoms often reoccur in the fall or following spring. Large patch can be controlled with fungicides applied in the fall and proper turf management.
Mole crickets and ground pearl are insects that live in the soil. Mole crickets are most damaging in the fall and early spring. They can kill grass in solid patches but are more likely to cause grass to appear thin and splotchy. You will often find narrow tunnels, about the width of a pencil, popping up in the soil where mole crickets are active and the ground may feel spongy underfoot. It is too late to treat for mole crickets this spring. Mole crickets usually reoccur in the same areas year after year. If mole crickets are the cause of your lawn’s demise you should treat infested areas in June.
Ground pearl are the most serious turf pest in our area. Symptoms are usually first noticed as small patches of grass that die and do not recover. Areas of lawn damaged by ground pearl slowly enlarge, expanding by up to a foot across each year. In most cases, nothing will grow back into the affected area except a few weeds. If you dig in the soil at the edge of the dying areas you will find the insects, which look like small round pearls about the size of a fertilizer pellet. There is no way to treat for ground pearl. If you find ground pearl in your lawn the only option is to plant infested areas with trees, shrubs, or flowers, or convert your lawn to a more vigorous turf grass that will better tolerate ground pearl feeding, such as ‘Celebration’ bermuda or ‘JaMur’ zoysia.
Repairing damaged centipede
If cold injury is the cause of dead patches in your lawn, repairing damaged areas is relatively simple. First, rake off the dead grass. Then either sow centipede grass seed or fill in dead areas with plugs or sod. The decision of whether to sow seed, lay sod, or plug damaged areas is usually based on cost. Sowing seed is less expensive but takes much longer to establish a dense lawn than laying sod or plugging. Plugs are small pieces of turf. They are less expensive that sod and fill in faster than seed. Plugs of healthy turf can be transplanted from other areas of the lawn to fill in dead spots.
The best time to seed, sod, or plug damaged areas is April through July. All newly repaired areas will need to be watered frequently until the seed, sod, or plugs become established. A 5-0-15 fertilizer can be applied at planting time to help new grass establish more quickly. For further advice on establishing and repairing lawns, visit NC Cooperative Extension’s Turf Files website (turffiles.ncsu.edu) and download a copy of the publication titled Carolina Lawns.
For assistance identifying and treating turf problems, contact your local Extension center. In Pender County, call 910-259-1238; in New Hanover County, call 910-798-7660; in Brunswick County call 910-253-2610. Or
post your questions to Extension’s ‘Ask an Expert’ widget, available online at ces.ncsu.edu.
Charlotte D. Glen is the horticulture agent with the Pender County Cooperative Extension of NC State University, College of Agriculture & Life Sciences. She can be reached via e-mail at Charlotte_Glen@ncsu.edu.