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Keeping Your Worms Warm and Cozy for the Winter


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.

6 comments on “Keeping Your Worms Warm and Cozy for the Winter

  • Hey all,
    It’s starting to get cold where I live and I want to being my worm bin inside, but when I do i notice some worms start crawling up the sides (not a mass exodus, just 5-10). The people I live with are skeptical about having the bin inside, and escaping worms would be a dealbreaker. Does anyone know why they are exploring and how to prevent that? Otherwise I’ll have to keep the bin outside and they might not survive the winter.

  • those who claim these worms will dig deep enough in the winter to keep from freezing forget we are talking red wigglers not run of the mill garden worm. It gets -15 and colder where I live and no matter what they freeze every year. Red wiggler won’t go more than 6-8 inches down.

  • Do you keep the lid on? Is there a lot of condensation? CAREFUL, when you take the lid off there may be worms on it underneath. some might fall off. But first put the worms back in the soil if there are any on the sides and lid. So leave the lid off a couple of inches.

  • I thought I’d chime in here, hoping maybe something I say will help someone, or inspire other ideas.

    I live in Maine, so it’s definitely very cold and snowy in the winter. – 20 to -30 degree windchills are semi common so heating worms can be difficult, or just plain expensive. I used to use plastic bins/totes, but now I have a 70 square foot room I built for my worms in my garage.

    METHOD 1—Since I grow an assortment of things all year long, I decided to use MH/HPS grow lights. My garage floor/first floor ceiling are extra protected with boards, tarps, and plastic. Good for insulation, and not rotting out the floor. The top of the worm bedding is covered by black plastic. I then put plant pots on top of that with a couple 600 watt lights (I dim them on warmer days). The lights grow my plants, and keep the black plastic warm which warms the bin. If I have no plants on top, I can lower my lights to about 12 inches above the plastic and it heats the plastic to 110-120 degrees Fahrenheit.

    METHOD 2—RISKY!!! I throw some Alfalfa pellets/green plant material in the bin (blood meal would work too). I either mix some in the top 2 inches, or I mix a good amount into a few holes in the bin. This causes the bin, or the holes to warm compost with the added nitrogen. This is very risky and requires knowledge and practice with hot composting. Too much nitrogen and your worms will cook. Hence, why I only do patches, or the top layer. The worms can surround the hot spots but if you mix up the bin, the whole thing will be hot.

    METHOD 3—This is an experiment I’ll be doing next winter. I sometimes compost in 45 gallon bins. When I mix manure and Alfalfa, then add a jug filled with a gallon of water to the center of the bin I can heat the water to ~130F. I’m going to pump that water through a hose that’ll coil around the worm bedding, pumping warm water all around it. Of course the water will cool but I’m still hoping it’ll stay above 90 degrees. I’ll most likely use a fish tank style pump, but as a fun experiment I’m going to test using anaerobic composting in containers, and use the gas pressure that builds to pump the warm water through the Hoses. One day I may even collect the methane from the anaerobic compost and burn that to heat water, but that might be a year or 2 away.

    Anyway, I hope something here helps someone or gives them a brilliant idea.

    PLEASE ALWAYS be careful when using any electical/heat/gas source.


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