Composting has been taking place in nature from the beginning of time. Leaves and branches fall onto the forest floor and slowly decompose, enriching the soil in the process. Composting in your backyard duplicates this process by breaking down yard and kitchen waste into usable soil amendments. The EPA reports that 23 percent of solid waste going into landfills is yard trimmings. What a waste when these nutrient rich materials could be composted and returned to the garden to replenish the nutrients.
Compost is the result of hundreds of organisms including bacteria, fungi, insects and worms feeding on organic matter. These organisms require four things to survive: carbon, an energy source; nitrogen, a protein source; moisture and oxygen. The decomposition rate is directly related to the number of organisms present. By providing a favorable environment for these organisms in your compost pile or bin you will soon have the dark colored, earthy smelling decomposed organic matter known as compost.
Although yard trimmings are the most plentiful source, there are many organic materials that can be composted. That list includes many things that you would normally not think of like cardboard rolls, shredded paper, coffee grounds and their filters, cotton rags, dryer lint and hair or fur. Some of the more common materials include: manure, eggshells, fireplace ashes, fruits and vegetables, grass clippings, hay and straw, nutshells, sawdust, wood chips and tea bags. There are also some things that should not be composted like, charcoal ash, dairy products, diseased or insect ridden plants, fat or grease, meat scraps or bones, pet wastes (dog and cat), and anything treated with chemicals or pesticides.
An ideal recipe for compost includes materials high in carbon or brown material like leaves, wood chips and branches plus materials high in nitrogen or green materials in the form of grass clippings, kitchen waste or vegetation. Green material is not usually as bulky as brown material and can be added in smaller quantities. A ratio of 25 parts carbon to 1 part nitrogen is recommended, although the process is more of an art than a science. Some gardeners report using equal parts of both carbon and nitrogen and achieve good results. A handful of soil or finished compost will provide the microorganisms necessary to start the process. It is important to keep the compost damp, about the consistency of a wrung out sponge to ensure the microorganisms do not dry out. Turning the pile frequently will provide oxygen to the organisms and speed up the process.
The composting process can occur in many different places. Some common methods include piles on the ground, freestanding bins, plastic bag composting, sheet composting, trench composting and using a commercial device called a tumbler.
Perhaps the easiest way to compost is to throw your yard and kitchen waste in a pile in the corner of your yard without worrying about carbon to nitrogen ratio or turning the pile. The pile will eventually rot although it may take up to a year. Composting this way may not destroy pathogens and weed seeds because the temperature within the pile may not get high enough. A more efficient method would be to use a compost bin. A bin can be constructed of wire fencing, concrete block, wood slats or purchased from a garden center. It should be no smaller that 3x3 feet and no larger than 5x5 feet to maximize microbial activity. It is important that the bin provides good air circulation and one side should be removable to provide easy access for turning. To begin the composting process, add repeating layers of 6 to 8 inches of brown and green material, followed by 1 inch of an activator like soil or manure in a bin (or substitute fertilize for an activator) and turn the pile weekly in the summer and monthly in the winter. Microbial activity will raise the temperature of the piles core to 140 degrees and destroy pathogens and weed seeds. The compost should be finished in about three months.
Bag composting is also an easy method. It involves placing leaves, preferably shredded, into a plastic bag along with two shovels of dirt or manure or ½ cup of high nitrogen fertilizer. Add water to dampen the leaves. Poke about 10 holes in the bag and place them in an out of the way spot. Turn a few times and add water if needed. Check on them after two weeks. The compost should be ready in about 6 to 8 weeks.
Sheet composting is composting without a pile. It is usually done near the end of the gardening season because it can take several months to break down in the soil. Use any organic materials that you would normally place in a pile. Leaves are plentiful this time of year and will work even better if they are shredded first. Mix together the compost materials and spread a 4 to 6 inch layer over your garden area, then incorporate these materials into the soil by using a tiller; or you can hand incorporate them by using a spade, hoe or garden fork. It’s a good idea to add some nitrogen fertilizer to the mix; it will supplement the process because decomposing carbon or brown material will draw nitrogen from the soil. By the spring planting season, your organic material will be decomposed and blended into the garden soil.
Trench composting involves digging trenches 8 to 10 inches wide and a foot or more deep in the garden. This is ideal for vegetable gardens. Backfill the trenches with shredded leaves and other organic materials, including about five shovels of manure or one cup of fertilizer for each 25 feet of trench. During the first year plant the rows along the side of your trench. In the second year make another trench on the other side of your planting row. In subsequent years locate your planting rows over the trenched areas. The compost will have dramatically improved the amount of nutrients in the soil.
If you want to go high tech, there are many commercial composting devices on the market that will mix and turn your compost for you. A compost tumbler is a barrel shaped device with air vents on the sides. As you collect material, you dump it in the tumbler and close the lid. Turning the handle once a day should yield compost in about a month. These tumblers make composting easy as long as you follow the basic guidelines.
Even with the best of efforts, sometimes the compost needs a little trouble shooting. If your compost pile develops a bad odor, it may be to wet and needs more oxygen. Try turning the pile and adding some dry materials. If your pile is damp and warm in the middle and nowhere else, it might be because your pile is to small. Collect more material and mix well to increase the size. If your pile will not heat up, it may still be too dry or does not have enough nitrogen. Mix in some grass clippings or fertilizer, moisten and aerate. These hints should get the process going again.
No matter which method you choose to use, composting provides huge benefits to your gardens as well as the environment. Compost enriches the soil, decreases the need for chemical fertilizers, suppresses plant diseases and pests, and increases production. Most importantly, composting reduces the amount of organic material destined for landfills. So get out there and start composting!