Preen Grass & Weed Preventer Plus Plant Food, 13 Lb.Use anytime during the spring, summer, or fall in flower and ornamental garden beds, around ground covers, trees and shrubs Prevents weeds and feeds plants in one easy step Balanced fertilizer promotes abundant blooms, increased yields and strong root development Safe for use around over 200 established flowers, vegetables, trees and shrubs One application feeds your plants and prevents weeds for up to three months