Create Amazing Soil: Planning for Spring, part 4

The most important part of growing abundance in your outdoor 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 nutrients needed by plants are nitrogen, phosphate, and potassium but there are many other essential minerals needed for healthy plant growth. It can be as harmful to have too much of a nutrient as to have too little. One of the most harmful impacts of industrial agriculture is the overuse of artificial fertilizers. The overuse of nitrogen, for example, is responsible for harmful algal blooms in the Great Lakes region of North America.

The best way to add nutrients to your garden beds is by using compost you create from your own food and garden waste. I have have three compost systems at work in my backyard.  One, is a 3-bin rotating compost systems that breaks down veggie and fruit scraps, plain grains (with no fats or sauces added), and garden waste. This creates most of the compost I use in my gardens.  I also have a small vermicomposting system that uses red wriggler worms to break down fresh food scarps. In return I get vermiculture – worm poop – which is an excellent fertilizer for the garden. I also have two biodigeester composers, one to breakdown cooked and high-fat food waste and the other to breakdown dog and cat poo. I do not add the compost from the biodigesters to my garden beds.

Manure is also a great source of nutrients in vegetable garden beds. However, most commercially available manure will be from CAFOS, or concentrated animal feeding operations. Not only are they a bi-product of animal misery but they may contain trace amounts of pharmaceuticals and pesticides which are routinely used in that industry. If you can source an ethical source of organic manure, it will be a great addition to your garden. My only source of manure at the moment is rabbit poop from Lola and Taj, who are animal companions (pets), and worm poop from the vermicomposting.

On occasion, I add extra minerals and natural fertilizers to my garden. In 2019, I filled in my in-ground pool to make a vegetable garden. The soil used for the infill was not rich in organic matter and so I made an organic fertilizer mix to amend the soil. I used this recipe, swapping out the animal products for minerals (as mentioned in the directions). I also made sure to source organic, non-GE soybean meal. I will be using this mix again in my annual vegetable garden beds to give veggies a needed boost of micronutrients.

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), I have found that it does not kill the critters living in the soil and, instead, actually utilizes them as allies in the building of healthy soil.

There is some controversy about the claims made by sheet mulching advocates. I have done some research within academic journals about using this method to start garden beds and have found very little peer-reviewed research, good or bad. The reality of science is that some interesting, important topics are understudied. If sheet-mulching works for you, like it does for me, use it! If not, use whatever method for starting new garden beds you like the best. I am not claiming this is the only or best way.

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

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

Materials:

• Cardboard, not waxed, with the tape and stickers removed
• Compost
• Straw NOT HAY (they are not interchangeable as hay has a lot of seed in it); can also used fine wood mulch or dry leaves
• 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 it
3. Spread a layer of compost over the cardboard, about 1 inch
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 inches
6. Put a thin layer of straw or wood mulch over the OM layer, about 2 inches

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 with a generous top layer of soil.

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. The most important rule to remember when building healthy soil is that you need to work with non-human nature. Artificial fertilizers and herbicides work against nonhuman nature in very harmful ways. When digging around in your garden, you should see a plethora or insects and other critters. This is a wonderful thing and means you are doing a great job!