Composting in the Winter

Composting in the Winter

Here in the desert we get most of our precipitation in the winter, when we don't have the warmth and sunshine for much growing. For growing crops we have to store and use winter's moisture to irrigate in the summer. With composting, we can do better. Active compost piles generate their own heat, even in the wet and frigid winter. If we can do some of our composting during the long winters we wont have to irrigate our compost piles much in the summer, meaning a major water savings here in the desert.

While information about composting abounds, there is little out there about how to manage the seasons of composting, specifically composting in the wintertime. How do you keep a compost pile going in frigid temperatures? Here are season-by-season instructions for my yearlong composting process:

Summer, year one: Progressively build the compost pile all summer long. While some composting will inevitably take place in the summer, you are basically just storing the ingredients for the coming winter's composting process.

Fall: With garden cleanup comes major additions to the compost pile. A good stopping place for new additions of plant material to the pile is after garden cleanup. Any animal bedding and manure is added at this time as well. In addition to plant material, always incorporate soil into the pile. It inoculates the compost with beneficial fungi and bacteria already present in the soil. It also holds onto moisture in an otherwise airy pile of plant material.

Winter: The bulk of our compost additions in the winter will come as food scraps from the kitchen. We continue to add these to the pile all winter long. With the exception of egg shells which we do not add any more of, these scraps decompose quickly and constitute small additions of green material to the pile.

In the winter the pile gets the bulk of its moisture. In some areas where winter precipitation is in the form of heavy rains, it is necessary to cover the compost pile to protect from leaching precious nutrients. We don't have that problem here, but we still cover the pile with transparent or black plastic to help facilitate it heating up during sunny days. This helps speed the whole process.

Composting in the winter requires more turning to heat the pile up and keep the process going. I'm always eager to get moving in the winter, so I turn it by hand. I use a pitch fork and progressively turn the pile over to a new space. This is where I'm really grateful to myself if I took the time to cut squash and tomato vines into smaller pieces in the fall because they are much easier to turn not being tangled with other plant material. They will also compost more quickly.

Turn the pile every other month. If you have a dry winter and notice the pile drying out, you may need to spray the pile down during one of the turnings. If snow has accumulated on the pile, treat it like an ingredient and just incorporate it into the pile while you are turning.

Spring: This is a good time to cover the pile with a tarp to protect it from leaching during spring rains.

Give it one last turn before doing so, and then let the process finish. The tarp should keep moisture in as well as, but look under occasionally to make sure it is not drying out. Start a new compost pile which will be next year’s compost.

Early summer, year two: Apply the finished compost and watch the plants grow!