Q: Our community has a problem with nutsedge in the lawns. Our landscape company recommended a product called Basagran. They used it on a test area but I was not very impressed. The company says it requires two applications, but they won’t guarantee anything. A local nursery recommended a product called Image. What do you think?
A: Nutsedge (nutgrass) is one of the hardest weeds to eliminate but it can be done with persistence! For conversation’s sake, try to determine first whether you have yellow nutsedge or purple nutsedge. Yellow has a folded, needle-like appearance at the tip while purple nutsedge leaves are a bit wider, gradually tapering to a point. Bentazon (Basagran) controls only yellow nutsedge.
The chemical imazaquin (Image) can be used to control both yellow and purple nutsedge in bermudagrass, centipedegrass, St. Augustine grass, and zoysiagrass but not in fescue lawns. If you have one of the permissible lawn grasses, you can spray imazaquin on the affected spot and then water it in.
Nutsedge control can also be gotten with halosulfuron (click for sources) but I rarely see it for sale in retail stores. Be sure to irrigate after application.
A new product is sulfentrazone (click for sources). This controls both nutsedges. Research suggests you’ll get best control with split applications 30 days apart.