Hi Yield Atrazine Weed Killer RTS is a ready-to-spray formula that controls both emerged weeds and weeds from seed in St. Augustine and Centipedegrass. It targets henbit, dollarweed, chickweed, clover, sandspur, and other listed weeds. Application rates are 5 teaspoons per quart to cover 100 sq. ft. or 4.3 oz per gallon for 500 sq. ft. For improved results, add Hi Yield Spreader Sticker and avoid watering for 24 to 48 hours after application.