Preen Garden Weed Preventer stops weeds from germinating in flower and vegetable gardens in ground covers and around trees and shrubs. Although Preen Garden Weed Preventer will not kill existing weeds it will prevent new weeds from sprouting - eliminating the need for difficult and time-consuming hand-weeding. Without weeds your valuable plants can grow larger and stronger. Apply Preen Garden Weed Preventer anytime during the growing season around established plants and transplants. Preen should not be used on flower seeds. It can be used after flowering plants have germinated and are 2-3 inches tall. Preen Garden Weed Preventer may also be incorporated into the soil when seeding vegetables (see the label for a list of vegetables it can be used with and how and when to apply) or applied after mulching beds. By applying Preen Garden Weed Preventer as early as possible you can eliminate the need for hand-weeding. Rain does not wash this product out of the soil. This handy shaker applicator bottle has a net content of 5.625 lb and covers 900 sq. ft.