William from Jacksonville, Florida writes
Drive XLR8 Herbicide is not labeled for use on St. Augustine grass. It will kill your lawn. We would recommend using Blindside Herbicide WDG. It is safe for use in St. Augustine grass and will eliminate actively growing crabgrass. You will use 0.15 - 0.23 oz. per 1,000 sq. ft.
Answer last updated on: 09/11/2019