Brown patch disease presents itself as brown and yellow spots that appear on your lawn and can be anywhere from 6 inches to several feet in diameter. It can be a very big issue in the mid to late summer season. Especially when the weather is hot and sticky as it is most likely to rear its ugly head when the weather is 80 degrees or above and not dropping lower than 70 degrees at night.
While there are several different types of conditions that cause dry, dead grass patches to appear in your otherwise lovely lawn during the summer, this one is especially common among tall fescue and other cool-season grasses. It comes from a fungus called Rhizoctonia that can be present in the soil of your grass for quite some time before popping up during the summer. The main causes of this disease include excessive nitrogen, which can come from using too much fertilizer, and also from overwatering.
The best ways to avoid brown patch is to water in the morning allowing your plants the entire day to soak it up in the sunshine instead of molding by being still being wet at nightfall. Aerating your lawn will also help improve circulation which will keep your lawn nice and healthy. If you are struggling with brown patches already you may want to have a fungicide applied which can help the grass get rid of the rhizoctonia.