Brown patch is not picky. It can affect any kind of grass. It particularly likes fescue, ryegrass, St. Augustine grass and centipede grass.
This disease typically appears during the height of the summer when the days and nights are both hot and humid. It favors lawns that are over fertilized, have a thicker thatch and those that are not properly watered.
This disease causes large circular shaped areas on your lawn. It can be easily mistaken for damage from dog urine or white grubs. The patches can be up to several feet in diameter throughout the lawn. The patches tend to be discolored. They are either a brownish or grayish color. Around the edges of the leaves and stems, the grass appears to be water-soaked.
When the grass is cut too short, the edges of the patch may appear to be a bluish color. This is called the smoke ring.
After a few weeks the grass inside the patch may green-up and recover.
Your first line of defense should be to check and possibly alter your lawn maintenance practices.
If your lawn is badly infested you can use a fungicide. Read the directions on the back of the package carefully before you use the product. Make sure the product controls brown patch on lawns. Always treat the affected and nearby areas.
A familiar characteristic of brown patch is the smoke ring