Ortho, Gallon, Concentrate, Groundclear Vegetation Killer, is formulated to kill weeds and grasses and prevent new growth for up to 1 year. To use this concentrate, simply mix 24 fl. oz. with 1 gallon of water in a tank sprayer. Use on areas where weeds are not desired, including driveways, sidewalks, gravel areas, rock and desert landscapes, under decks, on parking areas, along fences and curbs, and in unplanted areas. The fast-acting formula should be applied to actively growing weeds. You'll see visible results in 3 hours with Ortho GroundClear Year Long Vegetation Killer. Active ingredients:Imazapyr, isopropylamine salt: 0.47%, Pelargonic Acid and related fatty acids: 5.00%