Preen 10 lb. Extended Control Weed Preventer. Covers 1,630 sq. Ft. It is a one-time application that blocks weeds up to 6 months. It keeps 125 broadleaf and grassy weeds from sprouting. It can be used around more than 600 perennials, groundclovers, shrubs, and trees as listed on the product label. It is not intended for use on flower seeds, lawns, vegetable gardens, water gardens, or other food-producing or edible plants.