Sheet Mulching is a layered mulch system that will make your life as a gardener easier. Cardboard is most typical biodegradable weed barrier, but a thick layer of newspaper also works. It is essential that the barrier is permeable to water and air, so no plastic. As the materials break down, worms move in, and the health of the soil is significantly improved. Along with soil amendment, sheet mulching acts as a weed barrier and long-term mulch.
1.) Water the whole area thoroughly. This will help with future decomposition.
2.) Lay down a weed barrier. I prefer to use cardboard. Make sure to have a 4- to 6-inch overlap where sheets meet so buried weeds can’t find a route to the surface. This will smother existing weeds and prevent new ones. If you have already planted crops, or have other preexisting plants, cut holes in the cardboard to make some breathing space for each plant.
3.) Add a layer of compost and a layer of top mulch at least 3 inches thick. Water the whole bed thoroughly once again. Your sheet mulch bed is complete.
4.) Plant. To plant transplants pull back the top layers and cut an X in the cardboard. Then, pull back the corners of the X and put in the plant. Lastly, cover around the the new plant with the top layers again. For seeds, plant directly into the top layer.