How deep should a layer of mulch be?
Mulching depth is recommended at 2-4 inches. While deeper mulch can be effective in suppressing weeds and reducing maintenance, it often causes other problems, These include excess moisture, a change in soil pH, sour smells and a build up of toxic acids that can kill young plants. Additionally, thick blankets of fine mulch can become matted and may actually prevent the penetration of water and air and they can even act like potting soil and support weed growth.
