Preen 5 lb. Natural Vegetable Garden Weed Preventer Bottle covers 250 sq. ft. It is a natural solution for weed prevention that prevents crabgrass, dandelions, clover, and other common weeds. Safe for use around children and pets, this pre-emergent herbicide can be applied every 4-6 weeks. Simply sprinkle around established vegetables, herbs, and fruits once a month to prevent weeds from returning to your garden. Children and pets can play in the area immediately after application.