Spectracide One-Shot Weed & Grass Killer Concentrate2 works fast to kill unwanted weeds and grass. This powerful formula kills from the leaves to the roots and prevents regrowth for up to five months. Plus, it works quickly, with visible results same day. Clear out unwanted vegetation on walkways, driveways and patios. Avoid spraying this product onto desirable plants, lawn grasses, shrubs or trees. Spectracide One-Shot Weed & Grass Killer's formula gives you control over weeds and grass, roots and all. When mixed with water, this 32-oz concentrate formula covers up to 500 square feet. For best results apply during warm, sunny weather when weeds are actively growing and temperatures are above 60 degrees Fahrenheit. This formula is rain safe within 1 hour. Pets and people may re-enter treated area once sprays have dried. Use on patios, walkways and driveways