How To Create a Compost Sheet Mulching System

Using a Compost Sheet Mulching System

Sheet mulching is a layered mulch and compost system that can be used when creating or fortifying a landscape. Layered mulching is an economical way of decreasing weed growth, improving soil nutrient retention and increasing plant resistance to pests and diseases. To start your own sheet mulching system, place mulch on bare soil or on top of flattened weeds and follow these steps:

Step 1: Prepare your site for planting. Flatten existing vegetation and remove woody or bulky plant material. The organic matter left will begin to decompose and add nutrients to the soil. If you would like to expedite the decomposition process add 50lbs compost or manure to each 100 square feet of the site and then soak with water.

Step 2: Plant all plants that are 5-gallons or larger.

Step 3: Add two to three layers of an organic weed barrier which will break down over time. Do not add too many layers or use plastic as this barrier must be water and air permeable to allow for decomposition. Recycled cardboard, a thick layer of newspaper, burlap bags or old carpets made from natural fibers all work well. Ensure the pieces of the layers overlap by approximately 6 to 8 inches to cover the site completely except for any intentional holes. Leave a large opening around the root crowns of the plants to allow for air circulation. Wet the new barrier with water to keep it in place.

Step 4: Create a 2-5 inches deep compost and mulch layer using chipped plant debris, tree prunings, and leaves or straw. This layer must be free of weed seeds. Weed-free compost that is well decomposed can also be used as long as it is spread over the weed barrier and covered with bulkier materials such as chipped tree prunings.

Step 5: Plant. Create holes in the weed barrier and plant in the soil under the sheet mulch, or into the compost/mulch layer for small plants. If compost was not added in Step 4, add a small amount of compost around the rootballs of plants.

Helpful Tips:

  1. When using any type of mulching technique avoid plant disease by ensuring that materials are not piled up against the trunks or stems of plants.
  2. Protect small seedlings during the dry season from snails and slugs that seek moisture under the mulch and threaten new growth.
  3. Place physical guards around saplings to decrease the risk of destruction by rodents.

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