Kill the toughest weeds and grasses down to the root with Roundup Ready-To-Use Weed & Grass Killer III! The formula is ideal for use in and around vegetable gardens, flower beds, tree rings, and mulched beds, as well as on cracks in driveways, walkways, and patios. This convenient, no-mix formula is rainproof in just ten minutes-AND you get visible results in 3 hours. Kill weeds faster with Roundup.