Peat moss is a dark-brown; fibrous natural material formed from the decomposition of sphagnum moss and other organic materials in peat bogs. It is primarily used as a soil amendment to improve soil structure; aeration; and moisture retention for gardening and potted plants. Adding peat moss will help to reduce the pH of alkaline soils; making a better growing environment for plants that prefer slightly acidic to highly acidic soils; such as azaleas; camelias and rhodendrons. Peat moss is harvested from bogs and is a key component in many soil mixes.