Derived from Iron, Captain Jack's Lawnweed Brew offers selective control of weeds, disease, moss, algae, and lichens in lawns. The active ingredient is derived from iron, which occurs in nature. Kills many common weeds like dandelion, clover, moss, narrow-leaved plantain, chickweed, and thistle. Works quickly, as dying weeds will be seen within hours of application. Not for Sale in IA, KS, NE, PR, RI, SD