What is composting?
How to Compost
Composting requires only four basic components: air, water, and a suitable balance of brown materials (rich in carbon), such as autumn leaves, wood chips, shredded paper, and cardboard, together with green materials (rich in nitrogen), such as green leaves, grass and flower clippings, coffee grounds, fruit and vegetable scraps, horse and cow manure. Some things should not be composted: meats, cheeses, and fatty foods. A more complete list of materials to include and exclude in your compost, and why, are listed at U.S. EPA’s Composting at Home web page.
The addition of green materials speeds the decomposition of brown materials; but without adding sufficient brown materials, greens decompose too quickly into foul-smelling materials. A 1-to-1 to 2-to-1 balance of brown to green materials usually works well. Add water, if needed, to keep the mixture just slightly moist (“like a wrung-out sponge”). Turning the compost by hand every few weeks provides the needed aeration.
Complete degradation, to a dark, rich, earth-like-smelling product, usually takes several months or more. Starting a batch in the early spring will often produce compost you can use to enrich your garden in the late fall. The time required depends on several factors:
- Too much brown and too little green material slows the process;
- Starting with finer materials (shredded paper, smaller pieces of fruit and vegetables, mulched leaves) speeds degradation; and
- Placing the compost where it receives warmth from the sun accelerates the process.
When organic materials are properly composting, they also produce their own heat (100° F-140° F) especially during the first few weeks, which render weed seeds and pathogens inactive.
Yard Waste Composting
Food Waste Composting
Yard and food waste are commonly composted together. To address possible concerns about food waste attracting rodents and other pests, Montgomery County’s guidance is to compost food waste (together with brown materials) in rodent-proof bins.
Suitable bins can be constructed by homeowners or purchased online. Commercially available bins for food composting at home are available for purchase from various vendors, including rotating bins that facilitate aeration. Prices vary from $50 to $300, or more, depending on bin capacity and design. (Montgomery County is currently conducting a pilot test of rodent-proof containers suitable for food composting that could be offered to homeowners in the future.)
Homeowners also can subscribe to a weekly pickup service of food wastes from local commercial composting services. Two composting pickup companies that service our area are Compost Crew and Key Compost. These services typically charge about $30/month, but offer substantial cost reductions to groups of neighbors, towns, and communities that sign up for their service.
Another option for composting food waste is to deposit it at a free composting drop-off site nearby in Gaithersburg: Compost Drop-Off Site | Gaithersburg, MD