Composting is a simple way to make a nutrient packed growing media, reduce the amount of trash sent to the landfill, and support the environment. Compost provides nutrients for your plants, improves the texture of the soil, encourages the growth of beneficial microbes, retains moisture, and moderates soil temperatures. It has also shown promise as a natural pesticide against nematodes.
A natural process of decomposition, composting breaks down organic waste – yard debris and food scraps. The resulting product is a loamy media-rich in nutrients and live microbes.
The purpose of a compost bin is to contain the materials and keep animals out.
Commercially available compost bins, ideal for small residential properties, are closed on all sides and the top. The biggest drawback is the difficulty in turning the compost. A compost tumbler is the most effective means of producing compost quickly. Tumblers are elevated on a stand, rotate easily, and keep rodents out. The ideal tumbler has double chambers – one compartment for maturing compost and one for current additions of organic matter. If managed properly, a tumbler can produce compost in as little as six weeks.
You can make a compost tumbler with a heavy-duty garbage can that has a secure lid. For aeration, drill rows of ½” holes at 12″ intervals around the sides of the garbage can. To tumble, simply turn the garbage can on its side and roll. A simple bin can be constructed of inexpensive materials or items you may already have on hand: cinderblocks, wire fencing or discarded pallets. Even a plain pile will work.
Regardless of which container or method you choose, be sure to place the composting operation in a sunny location. The pile must heat up to kill any weed seeds and increase microbial activity. Ideal temperatures are between 130 and 150 degrees Fahrenheit.
Composting requires four ingredients – nitrogen, carbon, water, and air. Nitrogen comes from ‘greens’ – grass clippings, produce scraps, eggshells, coffee grounds, weeds that have not gone to seed, and manures. Do not compost meat and seafood scraps – they will attract pests.
Carbon comes from ‘browns’ – dried leaves, small twigs, shredded newspaper, cardboard, and paper egg cartons. Clean sawdust – free of paints, stains, finishes, and machine oils – can be composted. Scatter thinly, so that the sawdust does not form clumps. You should never compost any part of the black walnut tree. All parts of the black walnut contain a natural growth-inhibiting compound that can stunt growth and even kill plants.
The preferred ratio of materials is approximately one-third green to two-thirds brown.
Add materials in alternating layers. Add water to keep the pile moist. To check for ideal moisture content, squeeze a handful of compost. It should feel like a wrung-out sponge. Add water if it’s dry. If your pile is too wet, you can adjust it by adding additional carbon sources.
The compost materials must be turned to add air. Air provides a critical piece of the decomposition process – it oxidizes carbon, breaking it down.
A Few Tips
Start your compost on the bare ground so that earthworms and other beneficial organisms have access to your pile. Countless microorganisms digest and break down organic matter into the perfect plant food. Once in the garden, earthworms plow through the soil, mixing soil and organic matter, aerating the soil, and regulating soil temperature with their tunnels. Their castings enrich the soil better than any commercial fertilizer.
The addition of nitrogen sources activates the composting process. To jump-start this process, add manures, grass clippings, young weeds, or comfrey leaves. Comfrey’s deep roots absorb nutrients from the subsoil, making the plants rich in nitrogen, phosphorus, and potassium. You can purchase commercially produced ‘compost activators’ at organic gardening supply stores.
Do not turn your compost more than once or twice a week. Any more would disrupt the heating process that kills the weed seeds and any diseases. Patience is a virtue!
Make sure that you cover all fruit and vegetable scraps. If left exposed, these scraps can attract flying insects, including swarms of fruit flies and yellow jackets.
With a properly balanced compost pile, odor should not be a problem. If it becomes a problem, however, you can add carbon-rich ‘brown’ materials. Lime and calcium also help eliminate odors.