One activity we have done on the MOOC about soil recently is to measure the amount of stones in our own parcel of land. Fortunately, my soil is pretty free of them, so they aren’t restricting root growth or increasing drainage, when I’ve got sandy loam, which hardly needs help that domain.
However, there is a plus side to stones. But rather than stones in the soil, this time I’m referring to rocks (or bricks, for example) on top of the soil. The benefits are twofold: the soil under them conserves moisture for longer and they hold heat, so they alter the microclimate slightly.
When I moved the coldframe yesterday evening (from the area where I intend to build another hugel bed to a spot I have cleared of chard), I noticed the soil under the bricks was indeed still moist in comparison with that which had not been so covered. So, I strategically placed other bricks around the garden to give various crops the benefit of water for longer.
Then it occurred to me that the walls of the coldframe, also being of brick, might make the environment for seedlings within somewhat warmer. In other words, taking it that my neighbours cut their conifers down before this winter (it’s on the cards), which would mean sunlight could reach the ground in my garden, the bricks might give any plants in there extra insulation….