Thunder Bay Permaculture: Mycelium in the Garden

Mycelium in the Garden - Part 1

Gardeners often freak out when they see toadstools growing in their garden.

But it doesn't have to be that way. In fact, if we replace "toadstools" with edible mushrooms then we have created another stream of productivity while at the same time fill a decomposition function within the landscape.

This post is about my experiments with mycelium not just as a source of tasty mushrooms, but as a decomposition accelerator in my sheet mulching system.

But doesn't accelerating sheet mulch decomposition mean you have to replace it more often I hear you ask? Well, yes it does. But the reason I sheet mulch is keep plant competition down, regulate soil moisture, and encourage soil biodiversity.

I actually want my soil to eat the sheet mulch and incorporate all those nutrients and organic matter into the humus. Since my sheet mulch contains a lot of woody material it makes sense that a wood eating organism will do the job for me.

I started with a used straw log that commercial mushroom growers use to grow primary decomposers like oyster mushrooms in. I could have used spawn, or a slurry, but this is what I had available to me locally.

Since the log contained oyster mushroom mycelium, I decided to incorporate used coffee grounds into the sheet mulch bed. I collected a week's worth of used coffee grounds from a local coffee shop and stored them in sealed 5 gallon pails to prevent molding.

The 4ft wide garden bed I was working with had about 6ft of available space. It had some old newspaper and straw from last season on top of the soil, and I spread out the 15 gallons of used coffee grounds as my base layer directly on top.

Next, I cut the plastic off the straw log, and sliced it up into disks about 2 inches thick. These I placed on top of the coffee grounds as shown in the images below: