Q: My Mama has just discovered nutgrass taking over her yard again. We thought it was gone a long time ago! She has purchased several products but is there any one super powerful spray or powder to take care of all these weeds that are trying to reclaim her yard?
A: Nutgrass is one of the hardest weeds to manage but it can be done with persistence! For conversation’s sake, try to determine first whether you have purple nutgrass or yellow nutgrass. The leaf tips of purple nutgrass are slightly folded, resembling a boat hull. The leaf tips of yellow nutgrass are completely pinched together.
The chemical imazaquin (Image) can be used to control both yellow and purple nutgrass in Bermudagrass, centipedegrass, St. Augustine grass, and zoysiagrass but not in fescue lawns. If you have one of the permissable lawn grasses, you can spray imazaquin on the affected spot and then follow a week later with CAMA or MSMA (Crabgrass Killer).
Repeat the CAMA sprays at 10 day intervals. CAMA can not be used on centipedegrass or St. Augustinegrass. The very best nutgrass control can be gotten with halosulfuron (Manage, Sedgehammer) but I rarely see it for sale in retail stores.