Sheet mulching is a great way to prepare a new garden site. Typically, the soil is laboriously dug and tilled, rocks and roots are pried up and hauled away, tenacious perennial weeds are battled with little success, and the whole process in repeated again next year, as the soil has returned to its previous concrete like state. Instead, we can take a page from God’s design manual. In the natural world, we don’t see expanses of bare soil, or tillers turning up the soil. Instead, a thick layer of mulch, gradually grading into topsoil, blankets the land. This layer holds water and nutrients, nurtures beneficial soil life, and protects the soil from wild temperature swings. It also works against “weeds,” God’s reset mechanism, which quickly colonize bare soil and restart the mulching process. We can gain all these benefits, and save a lot of work, by sheet mulching a garden.
In its most basic form, sheet mulching is a laying down a weed barrier, topped by a foot of any decomposable matter. The weed barrier can be cardboard or newspaper sections, depending on how ferocious the weeds are, and how large the site is. To get better results faster, however, a good mix of high nitrogen and high carbon mulches should be used, rather like building a large flat compost pile, for better decomposition. The weed barrier should cover the whole area, paths as well as beds, so that weeds can’t infiltrate from the edges. The best time to build a sheet mulch garden is in the fall. Come spring, the mulch has decomposed enough to be planted. And then you will never have to dig again; just put on a little more mulch occasionally, and pull up any weeds which sprout on top (they will be easy to pull from loose mulch.)
Sheet mulching is especially great for establishing perennial food ecosystems, which are a main focus of Permaculture.
Of course, nothing is perfect. For intensive, wide row salad production, biointensive or double dug beds, amended with plenty of compost, are a better way to go. And bare earth will heat up faster in the spring (though it will also cool off faster in the fall.)
Though we will have more than one style of garden on our site, sheet mulching will take up the bulk of the area.