Spectracide Weed & Grass Killer with Extended Control, Ready-to-Use, 1-Galllon EXTENDED WEED AND GRASS CONTROL: Kills all types of weeds and grasses down to the root, and prevents weeds from coming back for up to 3 months. QUICK-KILL FORMULA: Visible results in as little as 3 hours. RAINFAST: Rainfall or watering 15 minutes after application will not wash away effectiveness. READY TO USE: No mixing needed  spray to completely cover the leaves of the target vegetation. USAGE: Spray on patios and walkways and in flower beds.