How to Identify Nimblewill
Nimblewill (Muhlenbergia schreberi) is a warm-season grass growing in a cool-season lawn. It has very fine, thin blades with a gray-green color that’s distinctly different from the darker green of bluegrass or fescue. In summer it blends in somewhat, but in early fall it goes dormant and turns tan 3 to 4 weeks before the surrounding cool-season grass, creating brown patches in an otherwise green lawn.
In spring, nimblewill is the last thing to green up, staying brown for weeks after the rest of your lawn is green. This early-dormancy and late-green-up pattern is the easiest identification method: look for patches that are off-season compared to everything around them.
Why It’s a Problem
Nimblewill spreads by stolons along the soil surface, gradually expanding each year. It’s not unattractive in summer, but the months of brown patches in an otherwise green lawn (fall through late spring) make it a serious cosmetic problem. Like quackgrass and dallisgrass, there is no convenient selective control. Mesotrione (Tenacity) provides suppression with repeated applications but rarely eliminates established patches completely.
