Gardening on what was until recently a construction site, this spring it’s been hand-to-ground combat with very compacted soil in my yard. The combination of heavy machinery and heavy building materials that covered most of the area last year has taken its toll. Adding a lot of compost, aerating the soil, and fertilizing are the first rounds of reparations. I’m also trying to keep all the bare ground covered so as not to make the ground even more compacted.
According to a number of reputable sources, raindrops falling on bare earth are the cause of most compacted soil. Surprisingly, the aggregate effect of those thousands of tiny droplets hitting the ground makes a lot of impact, enough for natural aeration channels and air pockets to collapse. This causes the soil to become hard, silty, and unable to take up more water. It also makes it difficult for plant roots to find enough oxygen.
This confirms what I’ve noticed in gardening. Any entirely bare patch of ground usually has terrible texture. Rock hard, it turns from mud to dust very quickly, and it tends to look starved. As it starts compacting, bare ground very soon it loses the ability to support much in the way of plant life, creating determinedly empty spots that are hard to remediate.
The areas of my yard that are coming back to life the quickest are those that were blanketed with a combination of wood chips and shredded leaves last fall. This insulating layer breaks the impact of rainfall, and allows it to soak in gradually as the drops penetrate the surface layers. As the organic matter decomposes it helps heal the soil, and attracts worms and insects that are good aerators.
It will take years to fix what took rock piles, pallets of roofing shingles, and grading machines mere months to accomplish, but for most gardeners getting life back into squished soil shouldn’t be nearly as difficult. Remember that a covering of any kind- even live weeds- is preferable to exposed dirt. If you’re trying to fix an area of any significant size, consider sheet mulching; layering cardboard or paper with compost and leaves and letting the stack rest for a season.
There are lots of gardening projects that provide more instant gratification than the slow process of fixing wrecked soil. But ultimately there may not be any work in the garden more rewarding than improving the substance that our plants depend on.