What "mulch" means in gardening

Mulch is a layer of organic or inorganic material spread over the soil surface around plants to retain moisture, suppress weed growth, regulate soil temperature, and improve soil fertility. It can be made of various materials, such as shredded leaves, grass clippings, straw, wood chips, rocks, or plastic. Mulch also helps to prevent soil erosion, protect plant roots from extreme weather conditions, and add organic matter to the soil as it decomposes over time.