Preen Grass & Weed Preventer Granules allow you to enjoy a weed-free vegetable garden without all the work. Preen Natural Vegetable Garden Weed Preventer is a natural solution for keeping weeds from your garden. Use in your fruit, vegetable, herb and landscape beds anytime during the growing season to save time from back-breaking weeding. Formulated to control clover, bluegrass, crabgrass, foxtail, lambs quarters and plantain. Just sprinkle on once a month to prevent weeds from returning to your garden. Children and pets can play in the area immediately after application. Covers 250 sq ft.