Sheet mulching is a gardening technique that suppresses weeds and builds fertile soil. Thick layers of organic matter are placed on the ground lasagna style. The layers are then left to decompose ultimately creating a rich planting medium that's terrific for vegetable gardens and landscape planting beds. This simple method saves time and energy (no tilling!), suppresses weeds, increases the soil's water-holding capacity, feeds the microbes in the soil, improves plant vigor and health.