GroundClear Weed & Grass Killer Refill, Ready-to-Use, 1-GallonOrtho groundclear, gallon, ready to use, weed & grass killer refill, kills all types of weeds & grasses, absorb on contact & starts working immediately, for use on patios, walkways, driveways, landscape beds, vegetable gardens & under trees, apply any time of year when weeds are small & actively growing, apply directly to the weeds, rain proof in 2 hours, see results in 15 minutes, omri listed for organic gardening. Active ingredient: Ammonium