Composting in Cold Weather
by Sandy Swegel
It snowed yesterday. It’s going to snow again today. This makes me so happy because it means I get a vacation from work. My gardening business is a lot like a teacher’s schedule. Work like crazy most of the year then I get a wonderful interlude to catch up on the rest of my life. Working in the garden may come to an end during Colorado winters, but eating usually continues and we continue to make lots of food scraps that any gardener would hate to waste.
When I lived on acreage, I did all my food composting by sending it through the chickens. The backyard chickens loved food scraps and eagerly ran around when I brought the compost bucket. Even if it was just onion scraps and things they didn’t like to eat, they relished scratching it around and mixing it with the coop bedding and poop. Spring compost in the making.
Without chickens, there are still ways that you can compost in winter and capture your kitchen scraps:
1. Use your regular compost bin
I empty mine to about ¼ full of compost in progress with lots of worms. I fill it all the way to the top with dry leaves and sort of hollow out the center. The leaves don’t freeze solid and all winter I drop the scraps down the middle of the leaves. The leaves provide some insulation and the food scraps and leaves at the bottom of the pile are warmed enough by the earth that a tiny bit of composting keeps happening even when temps get well below freezing. The earthworms are slow but still keep working and reproducing.
2. Compost in a protected sunny spot
Keep a plastic (black if possible) bin against the house on a sunny side. I started with the bin half full of partially finished compost that hopefully has some worms already busy in it. The center, next to the ground, will stay unfrozen so the worms will stay alive. The compost probably won’t process much over the winter except on sunny days. You may need to secure it against raccoons or other varmints.
3. Make a trench
This takes a bit of planning before the cold weather arrives, but produces amazing results and saves time and labor. Dig a long trench right in the garden…about a foot deep and a foot wide. Leave the soil heaped right next to the trench with a rake nearby. I left the excavated dirt on the side of the trench. Every time the indoor compost bin was full, I just took it out to the garden and dumped it into the trench. If things weren’t too frozen, I pulled some of the excavated dirt on top of the food scraps. If there was snow on the ground, I just put the scraps on top, and eventually, it fell into the trench.
This process attracts all the worms to the trench. Some composting takes place in the Fall but most decomposition happens in early Spring. By early May, when it’s time to plant tomatoes, the compost is broken down enough that I can transplant my tomatoes directly into the filled trench that is crawling with decomposers and happy earthworms. If it was a very cold winter and the compost isn’t finished, just plant right next to the trench. Some people like to compost in trenches all year. They set up a three-year rotating system where they compost one year, plant the next and use the area as a walkway the third year. Pretty clever!
4. Make a windrow
John, the Worm Man, Anderson in northern Colorado keeps his worms happy all winter by setting up short windrows of compost, food scraps, and worms. He throws old carpet or tarps over the top. Periodically, he lifts the carpet and puts new scraps on top of the piles. The worms slow down in winter but keep working and reproducing. For small households, just make a pile on the ground and cover it with a tarp. The tarp keeps moisture and some heat in. Just slip the food under the tarp. Worms show up. This doesn’t work so well if you have raccoon or mice and rat issues.