Take control of your lawn with Ortho Weed Killer for St. Augustinegrass. This weed control product kills weeds to the root, and won't harm your lawn (when used as directed). Plus, this weed killer is rainproof in 1 hour and shows visible results in hours. Use this weed killer to control major broadleaf weeds including dandelion, clover, chickweed, and dollarweed. In addition to St. Augustinegrass (including Floratam), this lawn weed killer may be used on Bahiagrass, Bermudagrass, Kentucky Bluegrass, Buffalograss, Centipedegrass, Fescues, Ryegrass and Zoysiagrass lawns. Apply when daytime temperatures are below 90F. To begin spraying, attach sprayer to garden hose and turn the water on. Slide the switch to "ON" and spray only until the surface of the lawn is wet. Do not apply this product to Carpetgrass; Dichondra; Lippia; gardens including vegetables, fruit trees, vines, and berries; ornamental plants; seashore paspalum; and turfgrass types that are not listed on the label. One 32 oz. container of Ortho Weed Killer for St. Augustinegrass treats up to 2,500 sq. ft. of lawn.