Muhlenbergia schreberi
grassy weedUSDA zones 4–9Active: summerWarm-season perennial grass that creates light green to straw-colored patches in cool-season lawns. Goes dormant early in fall, creating a patchwork appearance.
Fine, flat blue-green blades; wiry, creeping stolons; turns straw-colored well before cool-season grass; short, thin seed heads.
No selective control exists. Either accept it or kill patches and reseed.
When: Assess in fall when nimblewill goes dormant (straw-colored patches visible)
Cover dormant patches with clear plastic in summer. Less disruptive than herbicide.
When: Apply in summer; reseed in fall
Tenacity can selectively weaken nimblewill in cool-season turf. Multiple apps needed.
When: Apply 2-3 times at 2-week intervals when nimblewill is actively growing
Active ingredient: Mesotrione — e.g. Tenacity
Kill patches in fall when dormant and reseed. Non-selective but effective.
When: Treat in early fall; reseed 7 days later
Active ingredient: Glyphosate — e.g. Roundup
Grass safety: always match herbicides to your grass species — products safe on Kentucky bluegrass can kill St. Augustine or centipede. Lawn Guardian checks this automatically against your lawn profile.
Lawn Guardian turns this guidance into a schedule timed to your USDA zone and this week's actual weather — and adapts every time you log what you've done.
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