The Best Time to Thatch Centipede Lawns

Checking the Thatch Layer

• Thatch is the layer of organic material that naturally accumulates between your centipede grass and soil. When a thatch layer is over 1/2 inch, your centipede grass is more susceptible to fungal diseases, insect infestations and growing problems. A thick layer of thatch increases soil moisture, reduces air flow and creates an environment favorable for harboring insects or fungal spores that cause disease. To check your thatch layer, cut out a 2-inch wedge-shaped piece of centipede turf and measure that brown spongy thatch layer between the soil and blades.

Best Time to Dethatch

• The best time to dethatch your centipede lawn is right after the grass starts growing for the season. Because centipede grass is a warm season turf type, it starts growing late in the spring. Typically, gardeners dethatch their centipede grass in late May, according to Clemson University. Before dethatching, your centipede grass must have greened up and been mowed. Dethatching dormant grass harms grass blades. Power dethatchers rip thatch through the grass blades, which causes harm to dormant grass.

Dethatching Preparation

• Mow your lawn before your centipede grass reaches 1 1/2 inches, as suggested by Clemson University. Centipede grass is kept between 1 and 2 inches in height. Only take off one-third of the grass blade at a time when mowing. Water your lawn a few days before dethatching. It is best to dethatch dry centipede grass; however, you want the ground to be slightly moist to help the power dethatcher rip the thatch up through the lawn.

Dethatching

• Set your power dethatcher's blades to a 2- to 3-inch spacing and 1/4 inch in the soil, as recommended by Clemson University. Avoid dethatching your centipede lawn when blades are set 1 inch apart to prevent harming your grass. Push your power dethatcher back and forth across the lawn. Rake up the debris. For centipede lawns that are thinning or have bare spots, overseed your lawn after dethatching. Fertilize your lawn with 1/2 to 1 lb. of nitrogen after dethatching.