Topsoil is the uppermost layer of soil. It is anywhere from two to eight inches in depth and contains most of the organic material that provides nutrients for plant growth. When putting in new plantings, it is both cost-effective and environmentally friendly to recycle as much of your old topsoil as possible. To do this, you will need to first screen out the rocks and other debris that accumulate in your topsoil over time and can affect drainage. For large areas, commercial screeners can be rented. The simple method given here is intended for screening small areas.
Recycle small amounts of soil by turning over the old soil with a shovel or trowel and removing any rocks, clumps of grass or other debris by hand, placing them in a bucket or wheelbarrow for disposal. To recycle a larger area, first decide how much topsoil you will be recycling and whether it would be easier to screen it using a bucket (small amount) or wheelbarrow (large amount).
Cut or purchase a piece of hardware cloth a bit bigger than the bucket or wheelbarrow you will use to do the screening. Make sure an inch or so of the cloth hangs over the edges of your bucket or wheelbarrow.
Work in sections to dig up your virgin soil and place it onto the cloth. Dig to a depth of several inches. Use a shovel or trowel to work the soil through the cloth, scraping it back and forth with your shovel or trowel. Keep working until all the loose soil has collected in the bucket or wheelbarrow and the rocks and other large debris are left on the hardware cloth.
Lift one side of the cloth and tip the debris into a sack, bucket or second wheelbarrow for disposal. Discard any clumps of weeds and grass. You will be left with clean, recycled topsoil in your bucket or wheelbarrow. Mix the recycled topsoil with sand or fertiliser, if needed, and place your recycled topsoil back onto the ground and spread it around.
You can make a simple frame for your screener out of two-by-two board cut into 20-inch lengths and nailed together to form a square. Attach the screen with nails. A series of finer screens can be used if you wish to separate your soil into different categories.