Hi-Yield Treflan Herbicide Granules Are A PreEmergent Herbicide That Stops The Growth Of Weeds And Grasses In Your Vegetable Garden, Flower Garden And Foundation Plantings. Do not use on ground covers. Keep children and pets off treated area until Treflan has been mixed with the soil to a depth of 1" to 3". For best results, make first application early in the growing season (April in the Quad Cities) and a second application 10 weeks later. Till your garden before application, not after. Treflan forms a barrier on the surface of the soil that does not allow seeds to sprout through. Tilling after application would break that barrier. Only a few vegetable seeds can be planted in Treflan treated soil. Most food and flowers need to be transplanted as bedding plants. 15 Lbs.