The mulch-generating polyculture for Mortal Tree’s PASSIVE garden system is going well. It’s the bed in Foundation for a future I am establishing with bricks.*
The intent for this bed, per A bit blunt method, was to shift the rocks every couple of months to kill off the grass underneath. This worked pretty well for most of the bed. I shifted the bricks in July and made a final small shift about a week ago. Above is the freshly shifted “mulch” around an amorpha.
I also tried covering a small part with grass mulch in May last year, and this took care of any weeds growing through the cracks. Below is the planting now. Like most fun times, there is a mess to clean up afterwards. This bed had a lot of fun last year. What you see is actually mulch I applied, the healthy comfrey, and some amorpha interplanted. I plucked out the little bits of green quackgrass, and look forward to some very lush, beautiful growth here come summer.
I plucked out the quackgrass when I shifted the rocks. Because they block sun and moisture loss, the rocks encourage the quackgrass to grow shallow, allowing me to just pick them up rather than pulling them. What roots did grow deeply are easily pulled because the soil is so soft under the bricks.
This soil conditioning is one if the main perks of using rocks. The soil life is everywhere, with centipedes, worms, spiders -even at this cold season. Soil between the bricks which heaved from the freezing over winter is unbelievably friable. It looks like it has been tilled.
Considering how low this soil is in organic matter, with a clay-coal base, with no amendments like sand or ever even being tilled before, I am very excited to already have such results. The moisture and soil life have brought it so far because I have created the right habitat, covering the soil. The organic matter is starting to accumulate.
Above are some amorpha leaves dropped last fall, which likely have brought in nitrogen the system formerly did not have. The plants were already beginning to nodulate in their pots when I planted them last year. If you would like to learn more about how I ensure they make nitrogen and get off to a good start, I have some notes here on Growing amorpha.
I also harvested some of the comfrey leaves last year, which I left around the plants I harvested from. This is breaking down into gorgeous soil, bringing in carbon the system did not formerly have.
Pictured is some broken down comfrey from a larger patch in the food forest. This new patch should be producing similar soil in the near future. It’s already well on its way.
*This could have been done with some large piece of canvas or the like, or a large piece of plywood. One of my clients decided to try clear plastic just to block water, which was still effective at removing the plants underneath.
I have found bricks/stones to be a great way of conditioning the soil, too. Good luck with your plantings.
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Thanks for chiming in Helen. I appreciate it!