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Best Ways to Protect Composting Worms in the Winter

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.

9 comments on “Best Ways to Protect Composting Worms in the Winter

  • 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.

  • Anamarie Fox says:

    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?

  • Alfred Stokes says:


    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.

  • George Reynolds says:

    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.

  • Alfred Stokes says:

    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!

  • 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

  • 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?


    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?


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