Preen Garden Weed Preventer is a pre-emergent herbicide that stops weeds before they start by creating an invisible barrier that prevents weed seeds from germinating in flower beds, vegetable gardens, and around trees and shrubs. This 22-pound bag covers up to 3,520 square feet and provides continuous weed protection for up to three months with a single application, eliminating the need for manual hand-weeding.

Safe for use around over 200 established flowers, vegetables, trees, and shrubs, Preen can be applied anytime during the growing season in spring, summer, or fall. The granular formula contains 1.47% Trifluralin as the active ingredient, with a biodegradable carrier made from corn cob and recycled newsprint. It effectively prevents 39 common garden weeds including crabgrass, chickweed, purslane, foxtail, and knotweed.

Application is simple: remove existing weeds, sprinkle Preen granules evenly over soil or mulch at a rate of 1 ounce per 10 square feet, integrate into the top layer with a rake, and water immediately to activate the protective barrier. Once activated, the product works continuously for 9-12 weeks, with reapplication recommended to maintain season-long weed control. Rain does not wash the product out of soil, but soil disturbance after activation may reduce effectiveness.

Important usage notes: Preen does not kill existing weeds and should not be used on lawns or on flower seeds. It can be applied after flowering plants have germinated and are 2-3 inches tall. Keep granules away from plant roots and foliage to avoid damage. The product is manufactured by Lebanon Seaboard Corporation and comes with a satisfaction guarantee.