The need to restore topsoil stems from a variety of causes. New constructions sites feature unconsolidated soils disturbed during the building process. Poor drainage and subsequent erosion cause topsoil to vanish quickly from the landscape. Poor maintenance and overuse of topsoil also diminishes this precious environmental commodity. True topsoil takes many years to form, but homeowners can begin the process with proper soil management practices.
Calculate the quantity of new topsoil that a site requires. Plan to add 6 inches of new topsoil to the existing soil level. Small gardens don't require hauling in truckloads of new topsoil. Gardeners can use bagged topsoil for addition to these sites. Restoring an entire lawn requires soil delivery. See Resources for a topsoil calculator.
Cultivate the entire area using a rototiller, shovel, rake or hoe. Stir up the soil to a 12-inch depth to promote better drainage to encourage breakdown of organic material in the soil and to eliminate compacted soil beneath the site. Stirring up the soil also promotes quick spreading of grass or plant roots. Level the soil surface with the surrounding terrain.
Mix amendments such as peat moss, compost or humus (organic material) into a pile of topsoil. Stir it up exactly as you would a box of brownie mix. Mix amendments into the topsoil in ratios of one part soil amendment to three parts topsoil. The addition of these components also improves drainage and the health of the topsoil. We want to invite biological activity in the topsoil to create a micro environment that features the perfect mix of organic material, rock particles, organisms, air and water.
Pour amended topsoil onto the garden surface and level using a shovel or pitchfork. This depth should be at least 4 to 6 inches to begin forming a sustainable soil base resistant to erosion. The addition of amendments will expand the quantity of topsoil that may increase soil depth. Don't worry about adding too much topsoil. The best soils feature at least an 8- to 10-inch depth of topsoil.
Add water to the topsoil to reduce the fluffiness of the material. Observe how drainage occurs on the site to address any potential causes of topsoil runoff.