Zoysia grass is a thick, hardy turf grass that is popular because it is disease-resistant and generally does not require chemical help when it comes to fending off infections and diseases. However, if your zoysia grass is inflicted with a disease, it will mar the look of your lawn. Knowing what signs and symptoms to look out for will help you keep your grass healthy and happy.
Heavy fertilization when night temperatures are above 68 degrees F often leads to this patchy problem. Brown, circular patches of grass start out small, but left untreated, they can take over the yard. A brown ring often forms around a patch of healthy grass. To prevent this problem, fertilize your zoysia in the spring when nights are still cool and irrigate your lawn either in late evening or early morning. You can also treat brown patch with fungicides.
This disease is characterized by small, round, pale or dead patches of grass that are about the size of a silver dollar and can grow to the size of your hand. If you notice these spots, check the blades of grass for lesions that cut across the blade and kill the upper part of the blade. You can control dollar-spot disease with fungicides, but in general, perking your zoysia up with a good dose of fertilizer and a single, weekly, deep irrigation will enable the lawn to fight this problem off on its own.
If a cloud of orange powder shoots out from your mower when you start cutting the grass, your zoysia most likely has a rust infection. Rust likes cool, moist conditions and tends to grow in shaded areas. Giving your zoysia grass a moderate dose of low-nitrogen fertilizer will usually enable the grass to fight the problem on its own. If this is not successful, mow every five days, catching and disposing of the clippings. If all else fails, use a rusticide on the lawn.