Zoysia grass is popular in many areas for its vibrant green color, thick ground cover and relative ease of care. Unfortunately, the same thickness of Zoysia grass that makes it so desirable for lawns also leads to its most common problem: a buildup of clippings, dead leaves and roots at the base of the grass that is known as thatching.
The Problems with Thatching
When Zoysia grass builds up a thick layering of thatch at the bases of its blades, the thatching can suffocate the root systems. Also, as the grass reseeds itself, new growth may take hold in the thatching rather than the ground. This can lead to problems with wind and water erosion, especially in areas where summer storms produce strong winds and heavy rains.
Getting Rid of Thatching
The only truly effective way to avoid problems with thatching in Zoysia grass is to prevent it from happening in the first place. This can be done with regular lawn care, including trimming the lawn with a bagging mower, which will prevent cut grass blades from falling down into the grass and beginning the thatching process.
Once thatching has been established, however, there are only a few ways to get rid of it. The most popular method, but also the most dangerous, is to burn off the grass and, with it, the layer of thatching. Because Zoysia grass has such a strong root system, the grass will come back once burnt off.
Before You Burn
In order to successfully and safely burn off your Zoysia grass and get rid of the thatch that lies underneath it, take a few important precautions. First, contact your local government to ensure that burning is legal in your area at the time you want to burn. Even areas where burning is legal may have a "burn ban" in place from time to time due to drought conditions. Second, notify your neighbors of your plan to set your yard on fire to prevent anyone calling the fire department. Let them know also what precautions you intend to take to keep your fire from spreading into their yards. Third, prepare to have to put the fire out at a moment's notice. Grass fires spread quickly and burn hot. Have one or more strategically placed hoses ready to douse the flames if they get out of control. Last, prepare your personal equipment. Wear long sleeves and pants, a hat, flame-retardant gloves and a dust mask to protect you from smoke and the possibility of flying embers.
Burning the Grass
The best time of year to burn Zoysia grass is in the early spring, just before the grass begins to grow and turn lushly green again. Carefully light the grass on fire in an area well away from anything flammable other than the lawn, and watch it closely. This will tell you which direction the grass is likely to burn and how fast. Continue to watch the fire as it burns--never leave burning grass unattended. As each area burns down, watch to be sure it also burns out and apply the hose to any areas that continue to smolder after the grass is burnt.
After all the grass you need to burn is gone and the fire has complete burnt out, you may want to rake over the ashes and break them up. Leave them on the yard, though--they will provide compost and fertilizer for the next generation of lush, green grass.