Corn Gluten Meal is a natural corn by-product that has historically been sold as animal feed and used as a common ingredient in many dry pet foods. University researchers discovered that amino acid chains abundant in Corn Gluten Meal prevent secondary roots from developing properly in germinating seeds.Thus, Corn Gluten Meal provides excellent pre-emergent weed control. It is effective with preventing germination of ALL kinds of seeds, so…it will also prevent germination of grass seeds, flower seeds, garden seeds, etc. You should wait about six weeks after application to start seeds following the use of Corn Gluten Meal. It will not interfere with established plants or with the development of newly planted bulbs or other starts you want to transplant in your garden.