Composting is an effective method for reducing the amount of waste taken to landfills and provides a benefit to garden soil by adding nutrients and organic matter to the soil.

The United States Environmental Protection Agency (EPA) has collected data on municipal solid waste (MSW) for over 30 years. The EPA reported 139.6 million tons of MSW were landfilled in 2017. The largest component at about 22 percent is food. Other compostable waste includes paper and paperboard, yard trimmings and wood.

To make compost you need brown and green materials. Brown materials are high in carbon (C) and include shredded paper, leaves, straw and sawdust. Green materials are high in nitrogen (N) and consist of vegetable scraps, grass clippings and coffee grounds. Combining the green and brown materials in a good carbon nitrogen (C:N) ratio and providing the mixture with water, air and heat is the formula needed for good compost.

Composting is both a science and an art. There are guidelines available to calculate the correct ratio to achieve the desired result in the most efficient way. However a simplified guideline for the C:N balance is to use a 2:1 ratio of dried brown materials to fresh green materials.

Some organic materials are not suitable for composting. They include oil, fat, grease, meat, fish, dairy products or citrus fruit. Hard to kill weeds and weeds that have gone to seed should be avoided and pig, cat or dog manure should never be added.

Composting can be a sophisticated system or a simple inexpensive method. Composting can be in piles on the ground or in containers. There are tumbler style composters for purchase or low- cost, easy to make composters. Whatever method chosen, it is important to mix or turn the materials. This helps to create air in the system and begins the process of decomposition of materials.

Troubleshooting problems is part of the process. A solution is often an easy fix.

If the compost pile is producing a bad odor, it may be too wet. Turn the pile and add shredded paper or another dry material.

If you notice an ammonia odor, the pile has too much nitrogen- add carbon materials.

If the pile does not seem to be decomposing or it is not heating up, the pile is too dry- moisten it and turn the pile.

If the pile is moist enough but not heating up enough it may be too small. Add more materials to create a larger pile. It may also need more nitrogen.

Warning! Once you have a system set up and producing rich compost out of materials that otherwise would have ended up in the landfill; it may be hard to stop. You could start volunteering to mow your neighbor’s yard for the grass clippings or start bringing home bags of leaves found on curbs.

The possibilities are numerous for methods of composting. Pictured is a mineral tub I use on my deck. I cover it with an old storm window to keep out animals. When I am home during the day, I uncover it to provide air and water if needed. I also mix in used potting soil and a few tablespoons of organic fertilizer to help start the decomposition process.

For information on composting and more, visit the University of Missouri Extension website at Contact Kathi for composting or other horticulture questions at

Kathi Mecham is a field specialist in Horticulture for MU Extension.