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 especially if the turf is undernourished. Moss control application turns the moss black. To improve the appearance of lawn, raking out and removing dead moss a few days after treatment is highly recommended. Following up with mechanical aeration to help relieve compaction is also recommended. Over seeding or slice seeding will help fill in bare areas.