Concern Weed Preventer Plus Is 100% Natural Corn Gluten Pre-emergent Herbicide. Safe for people, pets and wildlife. Use around roses, flowers, bulbs, vegetables, trees, shrubs, under birdfeeders and on lawns. Immediately safe after application. Possible allergic reaction to breathing dust when applying in some people. Works best if watered in and allowed to dry for two to three days. Natural 8-2-4 fertilizer. 5 Lbs. Covers about 250 sq. ft.