Composting is a natural biological process that degrades a diverse mixture of ingredients such as leaves, grass, plant material, etc. into a soil-like material called compost. These degraded organic materials (compost) can then be recycled by applying it to the soil. Composting is a good way to eliminate household and yard waste while at the same time improving garden soil. A healthy soil is critical to gardening success. Composting naturally happens, but we can help speed the process by utilizing techniques that enhance the microbe’s (bacteria and fungi) ability to do their job.
Composting can be pursued at many levels, from a gardener who likes to produce “black gold” to the operation of a multi-acre commercial composting facility. Gardeners who compost their own landscaping and food scraps can follow a few simple guidelines and needn’t worry about complex formulas, chemical equations, or studying microorganisms.
The most common way to compost is to collect organic matter in open piles or place the material into bins or barrels. It is important to use only appropriate organic materials in the compost pile, which includes almost any garden or table waste that is plant-derived. Exceptions are plant materials that may harbor disease, may include noxious weed seeds, or material that has been treated with a persistent herbicide. Materials derived from oily foods or animal products should not be included in a compost pile.
A compost pile is created by layering green plant materials, brown and woody plant materials, and garden soil. Once a pile is constructed, composting success depends on providing microbes with the conditions they need to grow and thrive, which are oxygen, moisture and nutrients. These needs are met by turning (mixing) the pile weekly, occasionally adding water to the pile to maintain good moisture, and adding a small amount of fertilizer that is high in nitrogen. Good compost can be created in as little as six weeks with proper temperature and ideal conditions. With less ideal conditions, it may take much longer.
An optional way to compost is to utilize worms. This technique works for composting inside the home for those who live in apartments or otherwise lack space for the more common ways of composting.
For a comprehensive discussion of composting principles, read University of Idaho bulletin, Composting at Home, or the composting section of the University of Idaho Master Gardener’s Handbook.
See the Penn State site for a simplified version of how do home composting.
Learn how to compost using worms from Washington State University.