Brown Patch Fungus

Brown Patch Fungus

Disease & Plant Health

Brown Patch Fungus runs rampant in Central Florida, usually in the fall when temperatures tend to start dipping below 80°F. Irrigation heads are putting out the water and watering times get pushed to their limit as homeowners each compete for bragging rights. As we all learn, there’s a balance between being efficient and being effective especially when it comes to watering. As we all envy the plush green lawn.

Turfgrasses Affected

All warm-season grasses, especially St. Augustine & Zoysia.


Brown Patch Fungus usually occurs from November to May when temperatures tend to drop below 80°F. Infection is triggered by rainfall, excessive irrigation, or extended periods of high humidity resulting in the grass blades being continuously wet for 48 hours or more.

Signs & Symptoms

Brown Patch Fungus usually begins as small patches that turn yellow and then reddish-brown, brown, or straw-colored as the blades start to die. Patches can expand to several feet in diameter. It is not uncommon to see rings of yellow/brown turf with apparently healthy turf in the center. Turf at the outer margin of a patch may appear dark and wilted. Brown Patch Fungus in Florida tends to get mixed in the Chinch Bug category so inspect the grass closely before attempting treatment.


To rid your turf of Brown Patch Fungus, you can do it yourself or hire an expert. Before you try doing it yourself, read up on the chemicals and treatment procedures available to a residential consumer (University of Florida’s Guide) since most of the preferred chemicals might not be available at Home Depot or Lowes. Obviously, we strongly recommend hiring an expert that can guarantee results.

Please note that for the diseased turfgrass to recover, it must be actively growing. Symptoms will not disappear until new blades develop and the old blades are removed by mowing or natural decomposition. As this is a cool-weather disease, the turf may be nearly dormant at the time of infection and recovery is often very slow. Proper fungicide treatments simply help stop the disease from spreading; they DO NOT promote turfgrass growth while it is affected by current weather conditions.

Proper applications of fungicide consist of a minimum of two (2) applications, which is necessary for control of the disease. We usually schedule these applications roughly 2 weeks apart. These applications will prevent the spread of the fungus to other areas of the turf while new growth fills in the damaged areas, weather permitting. This will not prevent the disease from returning completely in later months, in some cases, additional treatments are required.

Bottom Line

Properly schedule irrigation run-times to promote health and growth. Keep in mind that irrigation is only a supplement to natural rainfall. If you’re experiencing cooler temps and the rain is still coming, dial down your run-times on your irrigation system or turn it off altogether. If you find this cumbersome or time-consuming, consider hiring an all-inclusive landscape company so you can forget about it.