Many people assume they have to make regular trips to their compost heaps outside in the cold in order to continue composting throughout frigid winter months. However, you can easily compost indoors during the winter--with the help of a bin of red worms, that is. You can increase your chances of successfully composting indoors during the winter by being aware of important vermicomposting maintenance and care factors.
Indoor worm composting bins are typically wooden or plastic; if you opt for plastic, make sure you drill drainage and ventilation holes in the bottom and side of your bin. Size your compost bin based on the amount of organic food waste your household produces each week; as a general rule of thumb, you should allow 1 square foot of surface space for each weekly pound of food waste. You can purchase red worms by the pound. One pound of worms (about 1,000 worms) is typically able to consume about 1/2 pound of food waste each day. Bed your worms on moistened, shredded newspaper or dead leaves.
According to Canada's Office of Urban Agriculture, common foods that work well for worms include fruit peels, vegetable scraps, coffee grounds and crushed egg shells. Always bury the food waste under 3 or 4 inches of bedding to allow the worms to get to it more quickly. You can put used napkins or paper towels in the bin, but make sure you shred and moisten them with water before adding them to the bedding. Never put non-biodegradable materials, such as aluminum foil or plastic wrap, in your worm bin.
You'll need to feed your worms organic kitchen waste at least once per week to keep them alive; an easy way to feed them is to get into the habit of collecting your food scraps and placing them into the bin once daily. As the worms consume the waste each day, they'll produce dark brown castings, which mix with the damp bedding to create a rich soil amendment for your potted plants. According to Canada's Office of Urban Agriculture, your indoor worm bin should produce finished compost for you to harvest in about 10 weeks.
According to Loren Nancarrow, co-author of "The Worm Book," worms in an enclosed container can go into shock and die if they're exposed to below-freezing temperatures for long periods of time. Canada's Office of Urban Agriculture states that you should try to keep your worm bin between 40 and 80 degrees F. Many people opt to keep their worm bins in a convenient, out-of-the-way location in the main home, such as under the kitchen sink. If you choose to keep your worm bin in a cooler indoor location, such as your basement or garage, monitor the temperature daily to make sure it doesn't get too chilly for your worms.
Odor issues can be a problem with improperly maintained indoor worm bins. Avoid giving your worms food waste that tends to be smelly or takes a long time to decompose, such as meat scraps or dairy products. Make sure you size your worm bin correctly, as well, since providing your worms with too much food can also lead to odor problems. If the bin seems to be getting too moist, adding extra drainage holes may help.