Large Patch Disease
Thursday May 05, 2011 – Large Patch is a turfgrass disease that affects all warm season grasses including Bermuda grass, Zoysia grass, Centipede grass and St. Augustine grass. Lawns are the most susceptible to large patch infection during the transition into and out of dormancy. So, if you see this, it will be in the fall and the spring as circular areas with orange borders varying from 6 inches to 20 feet in diameter. If you have some damage in the fall you will need to be aware that it may reoccur in the same places the following spring; or it may occur only intermittently in either season. Flair ups in the spring that are reoccurrences from earlier will look to be sunken patches that are very slow to green up. Fungicides are usually required to stop the disease progression and are best utilized preventatively. The ideal scenario would be to have a fungicide applied in October and another in November, followed up with one in the springtime. The series of 3 applications at this timing will generally prevent any major damage from happening. If you wait till you see signs of large patch fungus before calling to schedule a treatment, you may experience a longer recovery time for the damaged areas. Other things to do that help in disease prevention is to maintain mowing heights above 1 inch and do not overwater. Make sure that you have proper drainage throughout the lawn and also core aeration and dethatching will help to reduce the thatch layer where the large patch disease resides the most prominently.