Have you ever wanted to compost at home? For home gardeners, composting can save large amounts of money over time. With the cost of buying compost by the bag, why not make our own? All it takes are the right ingredients at the right ratios, time, and attentiveness. Composting is the natural process of decomposition of organic matter. Organic matter includes but is not limited to, vegetable and fruit scraps, coffee grounds, grass clippings, straw, leaves, and plant cuttings. All we are doing when we compost is speeding up the decomposition process and being left with decomposed organic matter that can be used as a soil amendment.

How does compost improve soil?

Compost can improve soil health in your gardens and potted plants by returning organic matter to the soil. Increasing organic matter improves soil health and plant health in a few ways. Soils with higher organic matter can hold more nutrients without the nutrients leaching out and being wasted, improves moisture holding capacity, stimulates the development of microorganisms such as bacteria and fungi beneficial to plant growth, and loosens heavy clay soils and decreases soil compaction.

The basics of composting

Bacteria, Fungi, and Protozoans work to break down structural carbohydrates in the organic matter. For decomposition to happen, there needs to be the correct Carbon to Nitrogen ratio in the compost pile. A C:N ratio of 30:1 is ideal for composting microbes to do their work. Refer to OSU Extension publication “HYG-1189-99” for more information on Carbon to Nitrogen ratios.

Microorganisms decompose organic matter more quickly with increased surface area to break down, so shredding your organic matter will quicken the process. Compost piles that are smaller than three feed cubed (27 cu. ft.; 3-4 ft. tall) have a difficult time maintaining heat that is required for the composting process to happen. However, piles that are larger than five feet cubed (125 cu. ft.; 5-6ft. tall) do not allow enough air to reach the microbes in the center of the compost pile, so make sure that your home compost pile falls between these two sizes.

Compost needs the appropriate amounts of moisture in order to compost correctly. The best way to tell if your compost has the right moisture is by doing the “squeeze test”. The squeeze test is simple, take a handful of compost, squeeze, and if water runs out of the compost it is too wet, if the compost crumbles it is too dry, if it maintains the shape of the inside of your hand and no water is exuded, it has the right moisture. If too dry, simply moisten the pile down with a garden hose until appropriate moisture is reached.

Do not cover your compost pile with a tarp or any type of covering, this will decrease airflow and the needed oxygen that the microbes need to actively compost. Compost piles need to heat in order to decompose fully, temperatures should be between 90- and 140-degrees Fahrenheit. The heating process will kill pathogens and many weed seeds, this is good because as you use the compost you will not be spreading disease or weeds around your garden.

Temperatures should not accede 160 degrees Fahrenheit, any higher than 160 degrees and the microorganisms will slow down and eventually halt activity. Compost thermometers can be purchased online or at most farm stores. If the compost is too hot, it is time to turn the pile, this can be done with most garden tools or a front-end loader on a small tractor. If the compost pile is consistently getting too hot, the C:N ratio may need corrected and moisture levels changed.

At the end of the composting process, you will have a high-quality soil amendment that can be used throughout your garden and home landscape for improving soil health and plant growth. Not only will you have a great product for improving your soil, but you have recycled, and in many ways made something out of nothing.

For more in-depth information on composting visit Ohioline and search for publication HYG-1189-99.

Brooks Warner is the Ag & Natural Resources Educator at OSU Extension Clinton County.