Create amazing soil: planning for spring, part 4

The most important part of growing abundance in your spaces is to create healthy soil that is full of life. In healthy soil there is an abundance of life in the form of insects, spiders, worms, other invertebrates; bacteria, fungi, and other microbiota; snakes and other reptiles; and, yes, even mammals such as shrews, mice, and moles. These critters are essential in adding organic material to the soil with their excrement and their bodies when they die and in aerating it with their tunnels and homes.

In order for plants to grow they also need a diversity of minerals in the soil. The main minerals needed by plants are nitrogen, phosphate, and potassium but there are many other essential minerals needed for healthy plant growth. One of the biggest, and most harmful, inputs of industrial agriculture is the use of artificial fertilizers. The overuse of nitrogen, for example, is responsible for harmful algal blooms in the Great Lakes region of North America.

Building healthy soil without harming ecosystems is a key focus of permaculture growing practices. My favourite way to begin a garden, of any kind, is to sheet mulch. Sheet mulching involves smothering grass or ‘weeds’ and building up healthy soil. In contrast to tilling and plowing (or, gasp, spraying the whole area with glyphosate), it does not kill the critters living in the soil and, instead, actually utilizes them as allies in the building of healthy soil.

The best time to sheet mulch in places with cold winters is the fall. Your sheet mulched garden bed will have time to break down over the fall, winter, and early spring. The second best time to sheet much is in the early spring, at least six weeks before you intend to plant. However, I often find myself sheet mulching gardens during the third best time: mid-late spring a few weeks before planting, in which case I modify it as I will explain below.

Sheet mulching, like so many permaculture and organic practices, is labour intensive but it is fun especially if you have a great group of people to help you! Try organizing permablitzes, in which a group of people sheet mulch garden beds for one another.

How to sheet-mulch an abundant garden

Materials:

  • Cardboard, not waxed, with the tape and stickers removed
  • Compost
  • Straw NOT HAY (they are not interchangeable, in my opinion)
  • Manure or compost
  • straw or mulch

Steps:

  1. Clear the area by cutting down the grass or unwanted plants.
  2. Lay down cardboard (two layers if the plants below are particularly opportunistic) and water itsheetmulch water
  3. Spread a layer of compost over the cardboard, about 1 inchsheetmulch
  4. Lay straw down (down fluff it up too much) over compost, about 8 inches 

  5. Put organic matter (manure or compost) on top of the straw, about 2 inchessheet mulch 4
  6. Put a thin layer of straw or wood mulch over the OM layer, about 2 inchessheetmulch 5

Tips:

  1. If I am sheet-mulching a garden bed in the spring, I modify it but adding a layer of soil over the last OM layer
  2. Source organic straw because conventional straw can have some pesticide residue
  3. Be prepared for some seeds in the straw, this is not a ‘weed-proof’ garden bed
  4. Whatever combination of nitrogen and carbon rich materials you use, try to get the right depth, about 12-14 inches.
  5. Source big sheets of cardboard from big-box furniture stores

If I plan to start a garden bed to plant immediately and there is no time for the building up of soil, I take inspiration from sheet mulching and build up the bed on top of cardboard.

Sheet-mulching is a wonderful way to start a new garden bed, one in which you co-create healthy soil with the life that already lives within the soil. Like permaculture, sheet mulching, allows you to create community and build relationships with other people, other animals, and other natures.

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I learned my sheet-mulching technique from this fabulous article by Toby Hemenway.