This has been one of the worst years for Brown Patch caused by the fungi Rhizoctonia soloni that I can remember. This organism attacks several grass species. We saw a lot of it in Tall Fescue this year, I also saw it in Kentucky bluegrass, and of course, it usually hits creeping bentgrass every year. This morning at the research station, we had one of the worst outbreaks I have ever seen on creeping bentgrass green. The attached video shows the extent of the damage.
Brown patch usually goes away with a weather change and the damage recovers quickly. You can also treat it with fungicides. We decided not to treat the green with fungicides at this time because our NTEP bentgrass trial is on this site. Hopefully I can get some data on differential damage to the various experimental cultivars. If that happens, I will do another blog on the damage.
Here is the video. Notice the classic "halo" around the outside to the blighted area.
The symptoms went away after 3 days. We will let you know if they return.