Topsoil is the nutrient-rich upper layer of soil, usually 2 to 8 inches in depth. Naturally occurring topsoil takes about 100 years per inch to develop, however, you can make topsoil in just a few months through composting. Compost piles produce soil that is highly beneficial to growing plants by biodegrading items that you would normally throw away, such as grass clippings, leaves and organic kitchen waste like fruits and vegetables. If you start your compost pile in the fall, the topsoil will be ready for your garden by spring.
Choose a clear, level location for your compost pile. Compost heaps can produce an odor, especially in the initial stages, so it's best to put them as far as possible from the house and other structures.
Arrange the organic material in layers. Start with a 6- to 8-inch layer of high-carbon waste, such as dead leaves, plant stalks and twigs. Top that with a 2- to 3-inch layer of nitrogen-rich material, such as grass clippings, livestock manure and kitchen waste like eggshells, fruit and vegetable scraps and coffee grounds. Do not use fat-based items, such as meat scraps or oils.
Cover the organic material with a 1-inch layer of soil and dampen the pile with water. Continue to layer high-carbon waste, nitrogen-rich waste, soil and water in the same proportions until all of your organic material is used.
Leave the pile undisturbed for five to six weeks, then turn it with a pitchfork. It's important to agitate the pile to oxygenate it, which keeps the composting process moving. When the matter begins to break down, the temperature of the pile will climb and it may emit steam when it's turned.
Turn the pile every five to six weeks, watering it very lightly when it appears dry. When the pile has turned mostly to dark soil, shake it through a composting screen to remove large pieces of debris. Lay a 1- to 2-inch layer of your homemade topsoil on your garden bed as a mulch after planting seeds or seedlings, mix it in with potting soil and use it to enrich your garden soil.