Ortho Groundclear, Gallon, Weed & Grass Killer RTU Wand Begins Working Immediately. Quick, Visible Results. See Results In 15 Minutes, Ideal For Use On Patios, Pavers & Landscape, Kills All Types Of Weeds & Grasses, For Organic Gardening, OMRI listed for organic gardening. Rainproof in 2 hours (upon drying). Active ingredient: Ammonium Nonanoate.