The Autumn is upon us, and it will soon be Winter in North America. You might be wondering if anything needs to be done with your vermicomposting worms in cold weather. It’s true, you can take action to preserve your worms! They will actually die in cold temperatures. You have several options, so keep reading to find out what will work best.
Do Nothing: If you keep your composter outdoors and exposed, yes, the worms will probably freeze in the winter. It’s true that the action of compost produces heat, and the worms will migrate to the warmer spots. Hopefully, the worms will lay eggs. These eggs are just fine in freezing temperatures. In the spring, when things warm up, a fresh crop of baby worms might appear. If not, you can order more composting worms at that time.
Bury It: The earth itself is an insulator. If you have a simple plastic composter, such as a large barrel-type device, you can try partially burying the bin. Harvest some of the finished compost if the bin is really full, but leave several feet of bedding. Dig a hole and put the composter in. At least half of the composter should be above ground. The worms will migrate to the warmer temperatures in the bottom half of the bin. Keep feeding them throughout the winter. They won’t eat as much. You can grind up the scraps. Bury the food so it’s easy for them to find and so they don’t have to crawl out of their warm bedding to get it.
Insulate It. Another tactic is to place an insulator around the outside of your composter. Try foam board, shredded newspaper, or straw bales. The composting process produces a small amount of heat that you can try to trap. Place the insulation so your bin’s ventilation and drainage holes are not blocked. Insulating can be done outdoors or, better yet, in a protected area such as a garage or porch. You can add heat using a lamp or heating pad, but place them carefully so you don’t start a fire. Keep the lid on. Avoid direct sunlight, because your worms could actually over-heat.
Move Indoors: Taking some or all of your worms indoors will protect them from the extreme cold. This will let you continue to compost in a convenient location. It’s also more likely the worms will survive the winter, cozy warm in your house. You might want to harvest some of your compost before moving it, if the bin is too heavy. A corner of the basement, heated garage, kitchen or closet may suffice. If you take good care of your worm bin, you won’t have a big problem with flies, pests, odors and mold. Learn more about setting up an indoor worm bin. Our Worm Factory 360 is a good choice for both indoors and outdoors. If you already have a big bin outside, you can use the smaller composter indoors in the winter.
A Non-Problem in Warm Climates: If the air temperature where you live doesn’t drop below 57°F very often, then you don’t have much to worry about. Your composting and your composting worms will slow down when it gets cool, but they won’t die. Make their lives easier by feeding less and cutting the kitchen scraps into smaller pieces. A food processor is very helpful for this. Just make sure that when it rains, your worms don’t drown. Keep them protected from too much water from above, and make sure the bin is able to drain properly.
Even in cold weather, you can keep composting and building up your supply of free fertilizer. A compost thermometer is handy for monitoring the bin’s interior temperature. Decide now what you will do with your worms over the winter, and keep going with your vermicomposting program.