Compost is decayed organic matter that is odorless and rich in nutrients. In your home, organic materials including kitchen scraps, leaves or grass clippings can be converted into compost. Aerobic (oxygen-requiring) microorganisms are responsible for the decomposition of these organic materials. The microbes need food, moisture and oxygen to break down the organic material. The microbes generate heat which, in turn, removes harmful bacteria from the organic matter. At the end of the decomposition process, which can depend on a variety of factors including temperature and oxygen levels, the newly formed compost will not bear any resemblance to the original organic materials. The compost can now be taken and used in the garden. Compost plays a very important role in the garden. It contains plant nutrients and enhances the quality of soil or other growing medium. Organic gardens utilize compost for a source of mulch, a soil amendment, or supplement with potting mix. Although compost add nutrients to the soil, it is not a fertilizer, which is ideal for organic gardens.
A 1 to 3 inch layer of compost placed around plants will control weeds, conserve water and prevent erosion. It can also be used to amend soil in a new garden or pot. To amend soil, place a 2 to 3 inch layer of compost on top of the planting area. Use a garden rake or rototiller to mix compost with the top six inches of soil. To use compost as an ingredient in potting mix, silt compost through a 1/4-inch screen to remove large pieces. Mix one part of sifted compost with two-parts of commercial potting soil. Use this to plant flowers or vegetables in pots.