If you are feeling hot in the summer, so are your composting worms! Unless they are snuggled indoors in air conditioning, your wiggly composting helpers need help staying cool. A few precautions will keep your worms operational. What natural cooling techniques do worms have? Where should your worm bin go? When should you intervene? What’s the worst that can happen?
Natural Worm Cooling
Worm in the wild knows what to do when they feel too hot. They dig down deeper in the earth or bedding (such as manure or rotting vegetation). This moves them away from the hot sun, sultry air, and warm surface.
Worms do not have sweat glands. They cannot pant to cool off. These simple critters are some of the oldest on earth. Worms are somewhat at the mercy of their environment.
When you harness the power of worms for composting, you create a partly artificial environment. The bedding you provide gives them room, food, and moisture. Bedding needs to be a bit fluffy so they can breathe through their skins. Confined in a box or bin, worms cannot move somewhere else. Therefore, you need to help your composting worms to keep them cool.
Composting Bin Design for Cooling
The vermicomposting bin itself should have features that help keep the worms cool.
- A lid keeps the sun off and moisture in. Keep the lid on.
- Proper drainage holes help regulate moisture. If the bin gets too wet, the extra water can drain instead of drowning the worms. Some bins have a water collection area and a spigot.
- Sufficient ventilation helps prevent too much hot air from accumulating in the bin. Make sure the bin has air holes.
- Place a special worm bin blanket or newspaper soaked in water on top of the bedding. This helps retain moisture.
Where to Place Your Worm Bin
Your vermicomposting bin needs to be placed out of the sun in the summer. Sunlight raises the worm bin temperature significantly in hot weather. Place your bin in the shade. Under an awning, under trees or bushes, in the shadow of a building, or in an outbuilding are good locations.
Moisture for Keeping Cool
Your worm bin is getting some moisture from food. The kitchen scraps you place in the bin often have a high water content. Sloppy melons and juicy vegetables are especially high in moisture. However, evaporation during hot weather means your bin might not get enough moisture.
Worm bin bedding should have the consistency of a wrung-out sponge. If your bin is too dry, pour some water on top of the bin. Dechlorinate the water first, if possible, by leaving it out overnight. A clean watering can makes this process easy. Be careful! Too much water all at once could drown your worms! Pour, let soak in, and test the moisture level again.
Want to give your worms a treat? Add ice. Place plain ice on top of the bedding or buried in the center of the bin. You can cool and feed the worms all at once by freezing scraps and water together. Place kitchen scraps in a plastic container, add water, and freeze solid. Bury it in the middle of the worm bin. As the ice melts, the scraps defrost, providing a meal for the worms.
Worst Case Scenario
What happens if the worms get too hot? They dehydrate, die, and dry up. Finding crispy dead worms in your bin? Try to salvage your worms by providing moisture and reducing heat. Worst case, they may have laid eggs that will hatch when conditions improve.
Have your worms died from heat exhaustion? Interested in starting a worm bin? Order a composting bin and composting worms from Uncle Jim’s Worm Farm. We are the #1 supplier of composting worms in the USA. We have Red Worms for composting, and European Night Crawlers (Super Reds) for composting, fishing, and aeration. Also, check out our selection of indoor/outdoor composters.
21 thoughts on “Cooling Worm Composting Bins in Summer”
Will you send me a picture of your composting bin?
My 2ooo red wigglers have been in bin with 3 inches of peat moss for 3 months feed regurlywith scrAps &leaves.i noticed small hair sized worms in bin seems to be doing well.my ?is does the peat moss get eaten&become compost or do I have to separate worms from bedding realizing meet moss is also good for garden would it more beinfical to seperate. (It is hard to tell peat from castings being moss is also very dark
I bought my worms about 8 months ago. I don’t find many worms in my bin. The ones I am finding my worms are not moving much ( can worms be described as lethargic) Are they dying because its the end of their life cycle. I have kept my bin covered and out of dierct sun light also I think my moisture content is correct.
Thank you for this post. I live in central Washington and it can get hot during the summer. Yesterday the high temperature was 102 degrees Fahrenheit. It was too hot for me and if I had worms, I would think that it would be too hot for them. Maybe now, I might venture forth and procure some worms.
Thanks for this post. I live in a hot place too (Puerto Rico) where winter is actually a better season for worm composting. The information that you provided is getting me to think about worms once again.
Great and timely advice-I had to move my bin into the garage from the covered porch once the temperatures were constantly over 90. Our soil temps just couldn’t stay out of the red zone. Interesting though, the worms have stratified themselves by size in the bin layers: small/babies on top, medium sizes in the middle, big guys in the bottom tray.
My Worm Cafe is in my garage in N.C. I have a new home and no trees as of yet to keep them outside. That being said the garage door faces south and gets very hot inside. I keep the door open about 20″ and also treat them each morning and night to frozen water containers. I place them on top of a few sheets of folded newspaper. I found when I just let frozen cubes defrost in the bin it was getting too wet. Although the food I give them is always frozen. I keep a zippy bag in the freezer and add to it during the week and feed them about 1# of food each time.
In the winter, depending on what the night temperature will be I place towels, a rug, etc over the bin and sometimes leave a few towels on during the day, again depending on the temperature.
I have had my worms for over a year now and they seem to be doing just fine.
I ve started composting in big plastic drums. Mainly with flowers. I would like to know how to reduce the temperature . Is it remain through out period.
Hello Bhaswati;
The only way to reduce the temperature is to add less of the compost at a time. Like grass clippings, if there is a huge amount together, as it starts to decompose, it creates excessive heat. When you add these materials in moderation, it will not get as hot. It takes longer to get them composted this way, but if you add them all at once, you will get the high temperatures of the compost as it breaks down.
Uncle Jim’s
With the European night crawlers if the ph is not correct b4 putting worms in can it affect the worms
I have a compost pile with worms . its a 10ft long by 4 feet wide . i have tarps coveing it to keep the sun out . I use the worms for trout fishing . I notices that most of the worms are not in the top 3 inches of dirt . I’m wondering if they are going deeper due to the soil being cooler . i water it every other day for 1 hour with a soaker hose. should i put more top soil on it or use cocoa bricks . to retain moisture i have 2 bricks i got from Home depot to use in case i do. and should i shred newspapers with the bricks. It is getting hot here in Calif and i want to make sure my worms make it to winter . I do add food several times a week as well. from banana peels to coffee grounds to potato peels and old lettuce.
Could be your worms. Red wrigglers are the best for composting. If you use regular worms they will often die or flee the “pile” as conditions are too “hot” for them
I freeze empty soda or water bottles filled with water to cool my worm bins when the temperature will be over 90 degrees Fahrenheit. I bury them in the bedding. Before I did this, I had all of them die one over 100 degree heatwave. So sad and STINKY!
Having a problem with my worm bin. First we are hatching Black soldier flys. Dozens of them! There also seem to be white flies developing. And the worms are crawling up all over the lid and trying to escape. Feeding once a week variety of vegetables & fruit scraps etc. moisture seems to be good. Had to bring them in the house because the outdoor temperatures in Phoenix are 115+. Don’t like the bugs in the house at all.
What to do?
Hello Susan;
Usually when there are other insects in the bin, it is because there is too much food or exposed food that they are drawn to. It is best to remove all excess food scraps and pick out all of the Soldier Fly larvae that you can. Let the bin dry out for a few days and do not feed them. Stir the bedding with a garden fork and allow oxygen into the soil. Cover the top of the bin with dampened newspaper or cardboard, which will also cover any food you will add. Only feed the worms every 3-4 days or when the food is almost gone. When the bin has too much exposed and decomposing food, more than the worms can process in 3 – 4 days, it will draw many different insects.
If this does not work, you may have to change the bedding altogether and start over. Separating the worms from the compost and putting them into new bedding. We hope that this was helpful to you.
Can I put worms in my existing compost bin. I don’t turn it as often as I should so, I thought perhaps worms would help. I realize I would have to monitor the temperature which I don’t do now.
Hello Ivy;
If you have a tumbler type composter and do not turn it often, keep it in the shade and the top open or allow air flow through it, that will work fine for the worms. it is best to put it in the shade though.
I see tiny red “balls” all through my worms bedding. I know what worm eggs look like, these are far smaller. Any idea what these eggs could be?
I’ve only had my worms for about 10 days. They are eating the coconut coir we started with but are not eating any food scraps. Should I be concerned? Or will they gravitate to the food scraps once all the bedding is gone? And can they survive if they eat all the coir? Do I have to add more bedding?
I need some advice. I’ve recently moved from Oregon where I enjoyed composting in a tumbler with red wigglers for many years.
Now I live on what feels like the surface of the sun-greater Dallas Texas. I would love to once again compost with a tumbler and (red wigglers?) worms. My gardens benefited greatly from the castings and beautiful soil addendums.
My concern is I will cook them during those miserable hot summer days. Is it possible to compost with a tumbler (I used a tumbler because I can’t physically move soil etc ) and worms in Texas. I would not be able to move this set up into air conditioning during the summer.
I believe good healthy soil is critical to gardening. So if I can compost in Texas , I’d appreciate the benefits it brings.
Thank for your help.
Hello Cheryl;
If you can move it to the shade somewhere and keep the compost moist and even open the doors sometimes for air circulation, that would help greatly.
Uncle Jim’s Worm Farm