Nimblewill (Muhlenbergia shreberi)
Nimblewill is a warm season perennial grass that most often reproduces by seeds and spreading stems. It forms dense patches, often a foot or more in diameter, often in older turf areas. It has fibrous roots, and the stems often root at the lower nodes. Nimblewill produces blue-green, short, flat leaves up to 2 inches long. The long slender flower stalks appear in the late summer. They are borne both at the ends of stems and in leaf axils, are 2 to 6 inches long, and are cylindrical.
Occurrence
It tolerates both sunny and shady settings and is often found where growing conditions are moist. As with other warm season grasses (e. g., zoysiagrass and bermudagrass), nimblewill is dormant from mid autumn through mid to late spring. When dormant, nimblewill is a faded dull brown; the patches tend to appear fuzzy, somewhat resembling a scouring pad. In turf invaded by nimblewill, these faded, fuzzy patches are especially apparent when cool season turf is green and actively growing in spring and autumn.
Non-Chemical Control
Maintaining a dense, healthy lawn through proper turf selection, establishment, and maintenance is the recommended non-chemical control for nimblewill. Nimblewill is often a problem in shaded and/or moist areas where commonly grown turfgrasses are poorly adapted. Modifying the growing conditions by improving soil drainage, reducing shade, and increasing air movement may favor turf growth and increase its ability to compete with nimblewill.
Chemical Control
The recommended chemical controls are nonselective herbicides, such as is glyphosate, applied to green, actively growing weeds. In the case of nimblewill, the active growth period is from late spring through early autumn. Applications of glyphosate to nimblewill when dormant will not provide control. Keep in mind that glyphosate is a non-selective product that, if mishandled, can damage or kill desirable turfgrasses and landscape plants. Be sure to read, understand, and follow all label directions when using any pest-control chemical.
