Composting Part 2

Time and Temperature

The most efficient decomposing bacteria thrive in temperatures between 110F and 160F. Thus, the hotter the pile, the faster the composting. If you achieve a good balance of carbon and nitrogen, provide lots of surface area within a large volume of material, and maintain adequate moisture and aeration, the temperature will rise over several days.

Use for Compost

Compost contains nutrients, but it is not a substitute for fertilizers. Compost holds nutrients in the soil until plants can use them, loosens and aerates clay soils, and retains water in sandy soils.

To use as a soil amendment, mix 2 to 5 inches of compost into vegetable and flower gardens each year before planting.

In a potting mixture, add one part compost to two parts commercial potting soil, or make your own mixture by using equal parts of compost and sand or perlite.

As a mulch, spread an inch or two of compost around annual flowers and vegetables, and up to 6 inches around trees and shrubs.

As a top dressing, mix finely sifted compost with sand and sprinkle evenly over lawns.

Source: United States Department of Agriculture

Surface Area

If the microorganisms have more surface area to feed on, the materials will break down faster. Chopping your garden debris with a machete, or using a chipper, shredder, or lawnmower to shred materials will help them decompose faster.

Volume

Compost piles trap heat generated by the activity of millions of microorganisms. A 3-foot by 3-foot by 3-foot compost pile is considered a minimum size for hot, fast composting. Piles wider or taller than 5 feet don't allow enough air to reach the microorganisms at the center.

Moisture and Aeration

The microorganisms in the compost pile function best when the materials are as damp as a wrung-out sponge and have many air passages. Extremes of sun or rain can adversely affect the balance of air and moisture in your pile. The air in the pile is usually used up faster than the moisture, so the materials must be turned or mixed up occasionally to add air that will sustain high temperatures and control odor. Materials can be turned with a pitchfork, rake, or other garden tool.