Jonathan Green Corn Gluten Weed Preventer plus Lawn Food feeds the lawn while preventing crabgrass, dandelions, and over 25 other broadleaf and grassy weeds. For optimal results apply early in the spring- between March and early May- before weeds germinate. For improved weed control and greening apply up to 4 times a year, in early and late spring and again in early and late fall.
The key factor in achieving great weed control results with this product is the proper timing of the first application. This weed control must be spread on established turfgrasses before the weeds germinate because it is only effective before weeds break the surface of the soil. Do not use this product when seeding because it will affect the new grass seedlings as they germinate. Based upon the organic nature of Corn Gluten Weed Preventer it may take a few seasons to control severe weed populations.