Cold Weather Composting

You’ve done it! Over the summer you have constructed the perfect compost pile.  You added weeds and scraps from the garden, watermelon rinds from summer cook outs, and peelings from preserving your harvest.  Winter doesn’t mean you have to stop composting, but you do have to do things a bit differently to ensure your pile continues to break down scraps effectively.

Compost piles are alive!  Inside your compost pile is a thriving ecosystem of bacteria, fungi, and nematodes.  For example, actinomyces are a special type of anaerobic bacteria that play an important role in soil ecology.  They produce enzymes that help degrade organic plant material.  The goal of a compost pile is to break down organic matter faster than it would naturally decompose.

In the winter activity tends to slow down in the pile.  It happens to humans, so why can’t it happen to bacteria?  The dreary, gray days that often makes us want to go into hibernation (if only work, life, etc. would let us) also affect compost microbes, in a manner of speaking.  Warm outside temperatures in the spring, summer, and fall make soil microbes more active and speed up the process of composting.  Lower winter temperatures will slow down or can even stop microbe activity.  In your kitchen you basically do this same process in your refrigerator and freezer to slow or stop the decomposition of foods.  In the refrigerator that is a good thing, but not so much in the compost bin.

Compost piles are natural heaters.  As the compost breaks down, the bacteria produce heat.  This can help keep the pile warm on cold winter days.  To help it along you can also insulate your pile with straw bales, a tarp, or you can even bury your pile.  The center of the pile can be warm and actively composting because of the exothermic biological processes within the pile, but the outer layers are at the mercy of ambient temperature fluctuations.  Since you don’t want to lose that trapped heat, it is also important not to turn piles during the winter.  During the cold winter months a big compost pile will hold heat better than a small pile.  I recommend a pile of at least one cubic yard to help hold in heat.  A great insulating tool is fall leaves.  Pile them on!

Winter winds and low humidity can suck the moisture out of your compost pile.  The microbes need moisture to survive.  During warm spells in the winter, be sure to water your pile.  Leave it damp, but not soaking.  Too much water can smother some microbes.

Follow these basic steps to help keep the little guys in your compost happy.  Then, in the spring, they will greet you with a rich batch or beautiful, black compost.  Check out the video below on building you very own compost bin.  Click here to read the article.