Sheet mulching – saves time, builds soil, and smothers existing weeds or lawn without using herbicide.
Sheet mulching is an excellent way to convert lawn to garden beds without using herbicides or excessive labor. Meanwhile it can build soil and be accomplished with readily available materials.
Begin by mowing grass or other vegetation in the area you want to convert into a new garden bed. It can be as simple as layers of newspaper or cardboard topped by four inches of mulch to smother grass and weeds underneath. If this is started in the spring, the underlying plants will have died from lack of light and the garden bed will be ready for planting in the fall.A more diverse layering of material will produce a compost that will break down and build your soil. For this, layer:
- Soil amendments if soil test results recommend amendments (lime, greensand, etc.). Recommended if you are creating a vegetable garden.
- Thin layer of compost.
- Wet newspaper or cardboard, 1/4 – 1/2 inch thick.
- Thin layer of nitrogen source such as manure.
- Layer of straw or leaves (carbon source).
- Continue to alternate layers of nitrogen and carbon sources.
- End with a top layer of mulch.
This type of bed is finished when these layers have decomposed. It may take the entire growing season to decompose sufficiently. If you start in the spring, the bed will likely be ready to plant in the fall.
See the Xerces Society Organic Site Preparation for Wildflower Establishment publication for more organic site preparation methods and directions: