Herbicide tolerance in St. Augustine: There are some common turf herbicides that cannot be used in St. Augustine due to severe injury. Drive (quinclorac) and products containing quinclorac cannot be used in this turf species. MSMA, currently registered for golf course, sod, and rights-of-way use, also causes severe injury to St. Augustine. The sulfonylurea herbicides Monument (trifloxysulfuron), Revolver (foramsulfuron), and Katana (flazasulfuron) are not registered for use in this turf species.
Since St. Augustine has overall lower herbicide tolerance than bermudagrass and zoysia, one needs to pay special attention to rates when making applications. Often applications rates are lower for St. Augustine than other turf species. Treating small areas first to gain knowledge of turf tolerance when working with a new herbicide or herbicide formulation in St. Augustine is a good and safe practice.
