Lasagna gardening or “sheet composting” is a no-dig, no-till method of developing a vegetable planting area which is 100 % organic matter. Cardboard or several layers of newspaper are first laid down on top of soil, grass or weedy areas. Then layers of green and brown organic material are added to a depth of a foot or more. The depth compresses as the organic matter decays. The cardboard or newspapers kill annual weeds or grass by cutting off light. However, deep rooted perennial weeds like wild blackberry, bindweed (wild morning glory) and Canada thistle will grow through or around the layers. They must be killed before starting your lasagna bed.
It requires 6 months to a year of development before planting, depending upon what organic materials are used. The process can be speeded up by adding some high quality topsoil.
The only drawback with lasagna gardening is that the layers are sometimes not very uniform resulting in uneven moisture levels and irregular growth. I prefer to modify this method by mixing the layers with a spading fork or hoe.