Spectracide Weed & Grass Killer With Extended Control Concentrate is formulated to kill lawn weeds and grass and prevent weed growth for up to 5 months. This quick-kill formula acts fast to kill all types of weeds and grasses down to the root, for visible results in as fast as 3 hours. This product is rainproof in 15 minutes ? rainfall or watering 15 minutes after application will not wash away effectiveness. Spectracide Weed & Grass Killer With Extended Control Concentrate is a quadruple-powered weed and grass killing formula, with diquat, fluazifop-p-butyl, dicamba and oxyfluorfen. Use along fences, paths, patios, sidewalks, curbs and driveways and around established ornamental trees, shrubs, flower beds, plantings and buildings. Use for trimming and edging landscapes. For best results, apply in warm, sunny weather when the temperature is over 60 degrees.