¨ If you want to kill weeds organically then you should start as soon as the weather allows. Meaning when the snow is gone apply Corn Gluten as a lawn weed preventer.
¨ Corn Gluten prevents seeds of weeds and grass from growing. Since many weed seeds start to germinate in cool temperatures before crabgrass seeds this makes it necessary to apply corn gluten as soon as the weather breaks.
¨ Then corn gluten should be applied again in mid April for a better organic crabgrass control