Thanksgiving will be here soon, and there is not much left in my garden. In fact, the only thing in the outside garden is my cover crop of cereal rye and hairy vetch and a few carrots and parsnips. There is one part of the garden that continues year round: the compost pile, and this is your reminder to keep it going.
Although you may not be thinking about composting in the winter, you can keep your compost pile "alive," even in winter, with a little extra attention. Frigid weather outside can slow the decomposition process, but you can, with a little forethought, maintain that essential core heat.
Composting depends on the activity of bacteria and fungi that work together to break down the organic materials in your pile. Like other bacteria, they're most are active at warmer temperatures.
Decomposition may slow or even stop, but it will start back up as soon as the weather warms back up a little. As long as your compost is kept above freezing, it continues to work slowly throughout the winter putting you that much ahead in spring.
Microbes need a balanced diet, a mixture of nitrogen and carbon rich materials (also known as "browns" and "greens"). Your kitchen scraps, such as vegetable and fruit peelings, coffee grounds and houseplant trimmings are handy sources of nitrogen-rich ingredients or "greens."
For carbon-rich ingredients, or "browns," use straw, fallen leaves, shredded newspaper or sawdust. Add two to three times as much brown as green.
You can add small amounts of ashes from your fireplace or wood stove, which will enhance the calcium, phosphorus and potassium content of your finished compost. The key word here is small amounts.
It's still possible to compost in the winter, even if your pile is completely frozen. Keep carbon components such as straw or autumn leaves near your pile, and layer them with your kitchen scraps. In the spring, when the pile thaws, the layered organic matter will break down quickly.
Chop your kitchen scraps into smaller pieces to help speed decomposition, since the bacteria in your compost will not be working as quickly in the cold weather.
Another component for consideration is moisture. Winter winds and low humidity can suck the moisture out of your compost pile. The microbes need moisture to survive. During warm spells, water the pile. Leave it damp but not soaking.
In warm weather, frequent turning is the best way to keep microbes well supplied with oxygen.
But in winter, you want to cause as little disturbance as possible to the layer of insulation. Wait until a warm stretch or even spring to turn the pile. A long-lasting blanket of snow insulates compost from deep freezes, but it can inhibit thawing.
Leave it on piles to which you are not adding new material, but scrape it off when you put on a fresh layer. You can cover your pile with a canvas or plastic tarp to prevent heat and moisture loss more effectively than a layer of snow. Just remember to add water to the pile regularly when you've shielded it from natural sources.
The pile will work better with some kind of containment system. You can buy one or build one yourself; remember it is a compost pile, so it does not need to be fancy. Leave one side open or removable so you can "turn" the pile. A compost pile 1 cubic yard is recommended to keep the center core "hot." That would be a pile 3 feet wide, 3 feet long and 3 feet tall. That is a big pile for most, so if you don't have that much compost don't worry just keep piling it on and this spring it will all work out, somehow it always does.
Happy gardening!
Peter Sutter is a life-long gardening enthusiast and a participant in the MU Extension's Callaway County Master Gardener program. Gardening questions can be sent to [email protected].