Protecting Composting Worms in Winter - Uncle Jim's Worm Farm

Protecting Composting Worms in Winter

Indoor Composters, Live Worms, Outdoor Composters

snow in the winterAre sub-freezing temperatures on their way? Composting with worms does not have to stop in the winter! If you live in a cold climate, your composting worms can continue working when winter approaches. You need to make some decisions. Here are your choices:

  1. Do nothing.
  2. Insulate.
  3. Move the worms to a sheltered location.
  4. Move the worms to a heated location (such as in the house, heated outbuilding or basement).

Wild worms fend for themselves during freezing temperatures. They dig deep to stay warm. Composting worms are somewhat domesticated because they live in a habitat that you provide. Therefore, you have to take action to keep the worms alive over the winter. Or, you can do nothing, and your composting program will still probably be OK.

Do Nothing to Your Composting Worms

What happens if you just leave the worms outside? Worm activity slows down as the temperature drops. Below 40 degrees Fahrenheit, the worms will be at risk of succumbing to the cold. They will burrow toward the warmest part of the bin: the bottom and center.

Any organic scraps that you add will increase the temperature slightly. The process of decomposition generates some heat. However, this may not be enough to keep the worms alive.

When the conditions are right, adult composting worms lay eggs. Worms are simultaneous hermaphrodites. This means each worm has female and male reproductive organs. Contented composting worms exchange DNA and produce cocoons. These cocoons survive freezing temperatures. With a little luck, new worms will hatch in the spring. Therefore, leaving the worm bin outside in the winter probably won’t be the end of your composting program.

If the worm population does not start to rebound in warm weather, you can order more composting worms from Uncle Jim’s Worm Farm.


To keep the worms warmer, add insulation to the outside of the worm bin. Bales of straw, blankets, used carpet, Styrofoam, or even bubble wrap will suffice. Leave gaps so that fresh air can flow into the bin’s air holes. Be sure not to block the drainage holes.

We cannot guarantee that insulating alone will be enough to save your worms. Insulation can be combined with moving the bin to a sheltered location for extra protection.

Move the Worms to a Sheltered Location

A garage, shed, or outbuilding helps protect the worms from the elements. Less exposure to cold winds keeps the bin a bit warmer. Add insulation. You can try a heat source such as a seed tray warming mat or an incandescent light. Even a 7-watt night light can add just enough heat to keep the bin from freezing. If you use a light, add a worm bin blanket or newspaper to keep the worms in the dark.

Safety warning: Be careful to prevent a fire or electrocution. Keep heat sources and electrical cords away from moisture and combustibles.

Worm bins can weigh several hundred pounds depending on size and fullness. Harvest some fertilizer to lighten the load. You do not have to move all the worms or the entire bin. Perhaps you can set up a smaller worm bin in the sheltered location.

Move the Worms to a Heated Location

If you are cold, the worms are cold. Try moving your composting program indoors during the cold season. Find a secluded spot in the house such as a closet, under the kitchen sink, cabinet, or corner. If your outdoor bin is too big or dirty, set up a smaller bin for indoors. You can find small footprint composting bins on our website. Dig out all the worms you want to save along with some bedding. Place them in their winter abode indoors. A basement or heated outbuilding will also suffice.

As a bonus, you won’t need to trudge through the snow to feed the worms. Also, your composting program will continue at full speed. Warm worms are productive worms.

Winter is a time of dormancy for wild earthworms. Your domesticated composting worms can be left to the elements, or coddled. When conditions are right, these hungry critters will eat your kitchen scraps and produce free fertilizer for your plants.

Got questions about composting with worms? Check out our blog, buy live worms, and see our indoor composters. We ship worms year-round. They are guaranteed to arrive alive or we will send new ones. Send your questions to us on social media or through our website.




26 thoughts on “Protecting Composting Worms in Winter

  1. I have an old larger ice chest, that was used on the boat to keep caught fish on ice. It is insulated and has a built in drain plug. Will this be aduquit to over winter my worms in outside, I am in zone 7?Thank You, Tom.

  2. what are those little tiny red and white bugs all over my bin? It seems my worm count went way down. Are those bugs bad for my garden? if so, how do. get rid of them?

  3. Jim,

    I live in Maine, but my wife and I go to Florida for the winter. Unfortunately, I can’t take my 20 gal. bin of worms with me. My bedding is 50/50 coconut coir/peat moss. If I leave them in a 40F degree basement for 5-6 months, feed them and water the bedding well (not drown them), do you think they will survive for this long without additional food & water? Do they eat coconut coir and peat moss or should I put in lots of cardboard bedding to tide them over? Thanks for your advice.

  4. Alfred, as “Uncle Jim” says, the worms create egg-like capsules which will probably make it through the winter and hatch when it warms up in the spring. If I were you, I would add a good amount of organic material, kitchen peelings, coffee grounds, tea bags, etc., as well as some grass and straw to the beds before you go to Florida. The decomposing material will provide some temporary warmth. Insulating the bed will also stave off the cold temporarily. I have two compost tumblers outside, and they freeze solid in the winter, worms and all. I also have a “Worm Factory” from Uncle Jim’s in my minimally-heated workshop. In the spring I take worms from that bed and re-introduce them to the tumbling composters as needed.

  5. Happy to say, my worms survived the winter and are doing just fine. I can’t tell that I lost any at all! Kept them in a 40 degree basement all winter after a good feeding and ample moisture in their bedding. Also, lots of young worms are hatching. Thanks for the advice!

  6. I just got a vermihut bin how much beding do i put in the first layer there is only about 2″ when i add another section doesnt seem to be enoughbeding or am i doing somthing worng

  7. I live in Vermont and the weather right now is crazy…had my worms in the basement all winter, moved them outside when Temps were in the 60’s and 70s now it’s been snowing for a few days. The bins are very heavy so moving them is a problem. The weather get down to 30s at night, but not freezing. Should Imove them or leave them at this point?

  8. Can i use a light bulb hanging over the bin inside down in cellar that’s cool even in hot hot summer temps? Or could I wrap the outside of tote with a blanket or something?

    1. Hello Heather!
      You can keep a light on the worms at all times if you wish. This will help to keep them from escaping the bin if that is what you are trying to do? If the temperature in the basement is 40 our above at all times, you do not need to worry about them. below 40, you may want to use a blanket or something.

  9. I’ve been looking for a solar solution for my outdoor bin, in Brooklyn NY zone 7B. The only solar products I see are heat lamps for chicken coops. Would keeping a bulbb lit under my outdoor plastic flow-through worm bin help keep up the temp at all? With insulation around the outside of that? I’m afraid of starting a fire! Which is why I also don’t want to run a cord form the bin to an outside pug all season long. Bringing the bin in is not a option, but I could bring in at least some of the worms, to winter in my basement . . .Thanks for any suggestions!

    1. Hello Elizabeth;

      Heat Lamps can start fires, so we do not recommend that. Jean-Michel Tremblay has a post here that is helpful! They used a Reptile Heating Mat with bubble wrap to insulate their worms. Look that up and perhaps you can get more information from Jean? There are many ways to insulate the bin, you can find ideas on line if you search “insulating my worm bin” as well. We definitely do not recommend Chicken heat lamps or heat lamps. They are not safe.

    1. Hi Dennis,

      Straw is a great addition to your worm bedding! However, you would not want it to be your only form of bedding as it does not retain as much moisture as other forms of bedding.

      Uncle Jim’s Worm Farm

    2. Hello Dennis;

      You can certainly add straw to the worm bin. Straw takes a little longer to break down but it is fine to add.

      Uncle Jim’s Worm Farm

  10. I’m planning to keep my bins outside this winter (eastern MA) on a east facing back deck that will get morning sun.
    My plan is to line the bins, bottom and sides, with cardboard and put a layer of wood chips at the bottom of the bin underneath the bedding and food. I will also add shredded leaves so that the bin is full of material.
    As the wood chips decompose they should add at least some heat to the bin.
    Good idea? Bad idea?
    Thanks in advance!

  11. When I had chickens, in order to keep the water bin from freezing, I used a tin can and made a hole in it to fit an electrical cord thru with a lightbulb attached inside the tin can. Then set the water bin on top of it. The tin I used was from a tin of cookies that you can buy. This way the can stays warm and won’t burn. Depending on the size of the tin you can decide on what wattage bulb you should use. It’s a very safe way as to not worry about a fire.

    1. Hello Patti;

      Thank you for that information. That is a great idea and we have heard of many others doing the same, however, we would like to add that any electric run to any barn or coop without proper insulation and professional installation, is a danger. Chickens will peck cords and any exposed items that are interesting to them as they are very curious creatures. It is always best to take extra precaution and run wires through PVC or keep them out of the reach of chickens or animals if you cannot do a professional installation of lights and warmers.

      We wish you the best.
      Uncle Jim’s Worm Farm

  12. Thanks for your reply Patti.
    I would like to do this without using electricity though I do have access to an outside outlet.
    I forgot to mention in my original comment that I do also intend to insulate around the outside of the bins with styrofoam and hay.
    Thanks again for your response.

  13. We are going to test burying each of our 9 bins into large wood chip piles. Add manure under the bins. Then cover with black tarps. We have air holes on the sides. And fresh organic food inside. Thoughts?

    1. Hello Cheri;

      This sounds like something I would do! I believe it will work, the only concern is the worms may burrow out of the air holes into the ground and not be there in the bin, in the spring? I be3lieve it will work out otherwise. We have a lot of customer who bury the bins for heat reasons in the west and the south. It can be done for the cold as well I am sure. Let us know how it goes.

      Uncle Jim’s Worm Farm

    1. Hello Maria!

      We ship our worms 5 days a week year round, except for in extreme weather conditions. They usually arrive alive and well, but if not, we do guarantee a live delivery.

      Uncle Jim’s Worm Farm

  14. We are in Central Labrador, Canada. There is no native worms here. We bought the red wigglers about 12 years ago. A lot of our worms winter in the big (5’ft deep and 8 ft wide and long) compost bin, outdoor,covered in snow. It steams some so we know it has warmth. One night last week was -30C but it is usually in the teens.
    The indoor ones are in 50 litre tubs at about +15C above baseboard electric heat. I feed them weekly with ground vegetables and fruit.
    We mostly keep them for there ‘juice’ that we inoculate our charcoal with and their castings for making liquid fertalizer.

  15. I live in montana winter can get cold here notice this spring i have lots of worms in my garden i like to know if i put them in a bucket i had for my potatoes has holes in them has straw and chicken horse poop mixed in it will worms servive with dirt please let me know never done this befor

    1. Hello Denise;

      If you are keeping the bucket inside in the winter, they can survive in a bucket if you tend them over the winter months.

      Uncle Jim’s Worm Farm

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