Lilly Miller Moss Out! for Lawns kills moss in lawns so grass can grow into a thick lush turf. Moss grows on the soil surface in lawns where it competes with the turf, causing the grass to thin out and creating an excessive build-up of thatch. Shaded or poorly drained acidic areas encourage moss growth. Apply Moss Out! for Lawns to these areas when the moss is actively growing. Moss Out! for Lawns gallons covers 2,000 sq. ft. After applying you will see the moss turning black within hours.