If you live in Florida or another warm location, you may not need to worry about your worms over the winter. But your worms will start to die off if temperatures drop below 40 degrees Fahrenheit. They do best when the air temperature is above 57 degrees Fahrenheit. If you are unsure what temperatures your worms are experiencing, you can use a compost thermometer. Take the temperature in several spots to get a clear indication of the situation.
If you know the cold weather won’t last long, you might just add a little insulation around your worms. For example, you could add some old blankets, old carpets, old socks, dryer lint, hay bales, insulation foam, or bubble wrap – whatever you have at hand. But the worms still need some air and moisture, so make sure to leave some gaps in your insulation.
If you live in an area where frosts are a regular occurrence or where you regularly get snow, you have these choices:
Leave them in the outdoor bin. Your worms will bury themselves deep in the bin as a way to survive the winter. They might even try to escape and dig down in the soil. Make sure the bin has lots of matter that can rot and provide warmth as part of the decomposition process. For example, you could use apples that no one wanted to eat. If you are emotionally attached to your worms, though, don’t count on this generation of worms making it through the winter. Pray they will lay eggs that will restore the vermicomposter in the spring.
You could leave your worms outside and then enclose the worm bin with thick layers of insulation, using blankets, hay bales and/or other insulating materials. Leave gaps so your worms get fresh air. No guarantees they will make it, though. We carry several outdoor composters on our website.
You could move your worm farm to a warmer location such as your garage or shed. If it isn’t a heated location, you could add a heater above the bin. For example, you could add some seed tray warming mats or a light as a heat source.
You could move your worms indoors into the basement, kitchen or closet. This is definitely an alternative because a well-managed worm farm won’t smell. This certainly makes feeding the worms easy! Some people elect to use a convenient, smaller composter such as the Worm Factory 360 for indoor use. Note: A fully-stocked, large worm farm can be heavy. It can be as much as 200 pounds. So make sure you have a few people to lift it, and remember to bend your knees! Lighten the load by harvesting your black gold first.
You have to accept the fact that your worms will eat less in winter. They aren’t bears, but they still go into hibernation mode a little. Be careful, especially if you have your worms in a worm farm, not to overfeed them. Otherwise, acidic conditions can be created, and these will be hazardous for your worms. Uneaten food also tends to attract ants and other vermin.
Rather than waste your excess food during this period, you can simply put it in a freezer. You can thaw it during the spring and feed it to your hungry worms then.
If you get caught by an unexpected cold spell and your worms die off, don’t panic. Their eggs (which are yellow and smaller than a grain of rice) may survive so you might find you still have some worms in the spring. You can always order some more Red Wigglers from Uncle Jim’s Worm Farm to top them up when the weather warms up.