Your compost pile doesn’t have to go dormant this winter

By Bonnie Orr
WSU Chelan/Douglas County Master Gardener

bonnie orr composting.
Chelan County Master Gardener Bonnie Orr scoops out finished compost in 2019 from her “hot pile” that only takes a few months to break down vegetation. – World file photo/Don Seabrook
Bonnie Orr
Bonnie Orr – WSU Extension Chelan/Douglas County Master Gardener – photo by Don Seabrook, Wenatchee World

WENATCHEE — Composting is an essential, environmentally important process that all homeowners could practice. It is a means to lessen the need for larger and more costly wastewater treatment plants that process the vast amount of organic material flushed down the garbage disposal.

By composting, we have an opportunity to build richer soil that is easier to work and holds water more effectively. Who wouldn’t want a garden with beautiful, hand-made soil?

Many people who compost during the summer allow their compost piles to go dormant because there is no longer a huge source of green material such as grass clippings and garden debris. The compost pile you started last spring can continue to work beyond summer.

The compost pile becomes dormant because of the lack of water, lack of new material and decrease of temperature. The micro-organisms, invertebrates (bugs and insects) and worms die when they are too cold, too dry and too hungry.

The downside of a dormant compost pile is that you have to start from scratch in the spring to rebuild the populations of beneficial insects and bugs, worms and micro-organisms.

Composting experts at Washington State University recommend that a compost pile be in direct soil contact so the microorganisms and invertebrates can enter the material and convert it to compost.

I have found that if I dig a depression 12-18 inches into the ground on the 3-foot-by-3-foot area the compost pile will sit upon, the compost pile more likely will overwinter. This is because the depression below ground level, with the composting materials stacked above, provides a warm refuge for worms and other actively working organisms. When the weather gets really cold, they will move into this lower, warmer, below-ground level.

I have dug down into this refuge and found big writhing knots of worms and lots of larva and pill bugs in the unfrozen refuge. In addition, different bacteria that thrive in cooler temperatures begin working on the materials.

It is also important to prevent the compost pile from freezing during the winter if you want to continue the composting process. In November, as the air and ground temperatures fall, I surround my compost pile with a barrier of straw bales or large plastic bags filled with leaves. An outer layer of wood chips also can provide insulation. It is amazingly effective.

When it gets really, really cold, and if there is snow, I use the snow from my driveway and heap it on top of the compost pile and all along the sides of it. (You never knew how important compost pile placement was did you?)

The insulation and additional snow protection have prevented my compost pile from freezing. I continue to add new material, mostly kitchen scraps, every day or so. Wood ashes are not a good addition to the compost pile because they clump and lower the pH of the pile. Too much water will drown your “wee beasties” because evaporation has slowed.

During the less friendly winter weather, I gather the kitchen scraps in a 5-gallon bucket in the garage. You need a place that is not too warm so the scraps rot, and not too cold so the material freezes. I add these stored materials to the pile when I have shoveled a path to the compost pile.

With our winters becoming less severe, this might be the season for you to overwinter your compost pile. You can call (509) 61567-6540 and ask a WSU Chelan Douglas Master Gardener for information about establishing an effective compost pile.

A WSU Chelan and Douglas County Master Gardener column appears weekly in The Wenatchee World. To learn more, visit or call (509) 667-6540.