Composting in all forms helps to create a new layer of clean growing area for garden beds. By making beds that are a foot deep or more, food can be grown in a clean, relatively safe soil. Garden up – don't dig. As you sheet mulch, be sure to water each layer.
SHEET MULCHING is a fast, labor saving technique for building beds and suppressing weeds. For immediate planting, use perennials, large seeds, or make soil pockets for annual starts or small seeds. If you create new beds in the fall they will be ready to plant by spring.
Put down some manure, chopped yard waste and/or food scraps (about 6")
Cover with cardboard or layers of newspaper. (Do not use shiny color pages) Soak each layer. Finish with 6" straw or sawdust.(Do not bury sawdust or wood chips.) Make soil pockets for immediate planting or let sit a few months. Water regularly if weather is dry.
ANOTHER APPROACH (from Permaculture Activist)
Wet area to be mulched the day before you plan to mulch.
You will want to soak each layer as you put it down – moisture speeds up the decomposition process.
Slash existing vegetation. Don't pull up the weeds – it would disturb the soil and is not necessary.
Add soil amendments depending on soil type. Gypsum or lime and rock dust.
Put down a layer of high nitrogen material: chicken manure, fresh greens, whatever is on hand that is high in nitrogen.
Poke with pitchfork and rock back and forth to aerate heavy clay.
Spread several layers of newspaper or one layer of cardboard.
Spread a thin layer of food waste, decayed leaves or garden scraps.
Put down 6" of straw, leaves or grass.
Add 4" to 6" of finished compost, seaweed or well-rotted (3-month old) manure.
Finish with a layer of high carbon material: pine needles, straw, seagrass, leaves, wood chips, bark, sawdust or rice hulls.
First, plant any large trees or shrubs.
Sprinkle soil with dolomite (and gypsum for clay soil). Sprinkle chicken manure, blood and bone (for nitrogen). Optional – spread compost scraps for the worms.
Add weedy or seedy material. Do not dig, level or weed.
Sheet mulch with newspaper or cardboard – cover completely.
Apply 7.5cm of horse or poultry manure in sawdust or straw, leaf mold or seaweed.
Follow with 15cm dry, weed/seed free material: pine needles, rice husks, leaf mold, straw, bark, chips, sawdust or any combination. Water well.