Spring is all about plants, and autumn is a good time to renovate soil and prepare new beds that will be ready for planting as soon as frost leaves the ground. Often these activities begin with ordering several cubic yards of fresh topsoil or triple mix (equal parts topsoil, peat moss and compost) that are delivered and dumped in the driveway, and then must be moved by wheelbarrow. It’s hard to avoid the manual labour and brute strength required to move soil, and you might find it necessary to recruit strong arms for the task.
There are differences in the weight and ingredient content in every batch of purchased soil. You can try to find a supplier that provides clean soil with no weed seeds, chunks of wood or plant debris. You’ll also want your purchased soil to drain well, not form a compacted layer and have enough substance to last for years without shrinking or eroding away.
However, it’s also possible to manufacture soil customized to your purpose, using ingredients currently on hand. Clay, organic material and small particle rocks in varying amounts are the basic ingredients of every kind of soil. The different amounts of these materials in a soil mix determine the soil character: how well it drains; its potential fertility; whether it has a soft, root-friendly texture; and its ability to exchange water and gases efficiently.
One autumn about a decade ago, the lower branches of a mature spruce tree in my garden were blocking passage directly where a stone path was to be installed. It was necessary to high prune the tree, exposing a large area around the main trunk. I wanted to plant in this new vacant space, which had been concealed by branches for 70 years. (I actually know when that spruce tree was planted.) It seemed a good idea to bring in some fresh soil. Instead of attempting to dig amendments into ground thick with tree roots, I made a sloped, 18-inch (45-cm) layer of soil on the surface, and planted it with groundcovers. The area is about 15 x 35 feet (4.5 x 10.5 m) and would have required a substantial amount of purchased soil. This would have been expensive, and I wasn’t sure enough muscle would be available for the work.
I began to consider what’s involved in manufacturing a fresh, nutritious and quickly usable soil medium, and came up with an impromptu recipe incorporating clay (garden soil), organic material (leaves and manure) and rocks (coarse sand and grit). All the leaves from my property (and many bags taken from the road) were spread across the planting area. I threw on a few wheelbarrows of clay loam taken from other areas in the garden. Purchased bags of composted manure were dumped on the leaves, and then I did the same with bags of gritty construction sand (a dozen bags of each). Finally, a few liberal handfuls of high-nitrogen lawn fertilizer (to help compost the leaves) were cast over the spread out pile. I used a garden fork to roughly mix and incorporate the leaves and amendments, and it was all wetted down with the hose. I had help in bringing in the bags of manure and sand, but all the other work was easily done by myself.
I let the new bed sit for 10 days, and then planted it with two dozen hostas. The soil mix was rough and mostly leaves, but easy to work with. The leaves began to noticeably break down until frost halted the process and snow covered the site. In spring, the pile of manufactured soil warmed quickly and the leaves continued to break down. By the end of the following summer, the pile was a thick layer of crumbly soil.
Small leaves, or leaves shredded with a power mower, work best for this kind of recipe. The balance of ingredients can be customized to suit any purpose, and mine was certainly heavy on leaf content. This worked very well, and the new area slowly became lower as the leaves broke down. Tree roots did enter the new soil, but they haven’t strangled out any of the plants. The spruce tree and the new plants seem to have reached a healthy accommodation, and the gardener accomplished a huge task easily and at low cost. Sometimes the solution to a problem is right at hand.