Ortho GroundClear Weed & Grass Killer2 in a 32-oz. bottle covers up to 600 sq. ft. with the active ingredient Ammonium Nonanoate: 40.0%. One pint of concentrate mixed with 7 pints of water treats up to 300 sq. ft. This herbicide is a powerful way to quickly clear weeds such as dandelions, chickweed, nutsedge and moss, plus unwanted grasses from patios, walkways, landscape beds, gardens and under trees. Results are achieved in just 15 minutes. This weed and grass killer acts on contact, and most weeds turn brown in only 2 hours. This insecticide is OMRI listed, so you can apply with confidence. People and pets may enter the treated areas after spray has dried; and you can plant new flowers, trees and shrubs in the treated areas once the application dries (upon drying). In a tank sprayer mix 1 pint of concentrate with 7 pints of water to treat up to 300 sq. ft. For hard to control perennial weeds or extremely dense weed growth, mix 1.2 pints (19.2 fl. oz.) of the product with 6.8 pints of water to treat up to 300 sq. ft. Difficult to control weeds may require more than one application for complete control.