Preen Weed Preventer stops weeds from germinating in flower and vegetable gardens, in ground covers and around trees and shrubs. Although Preen will not kill existing weeds, it can be used as a grass weed killing alternative. 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. Your beds will stay neat and weed-free all season long! 5.6 lb bottle