Brown Patches in Your Winter Lawn
When you see brown patches in your lawn this time of year it is usually a different kind of grass from the one that is predominately growing in your lawn. For example, If you live in an area of the country that can grow both cool-season grasses (like Bluegrass, Fescue and Ryegrass) as well as warm-season grasses (like Bermuda, Zoysia and Centipede); you may have both types of grasses in your lawn. This means that during cold weather your warm-season grasses will turn straw-colored or brown when they go dormant while your cool-season grasses remain green.
So when you see brown patches this time of year, do not be too quick to blame them on fungus disease or insects.