Keeping your worms cool in Summer

Ice packs to keep worms cool.
Ice packs help a lot

Summer in Australia can be hell, so don’t forget your composting companions. Worms can suffer a lot in the heat and we need to take a little extra care of them. Here’s some ideas that we’ve found work well:

The first thing to do is to make sure your worm farm is in the shade. If it’s not in the shade, cover it with shade cloth or fabric – old sheets will do fine. Try and avoid plastic sheets as the heat can soon build up under them. If plastic is your only option, make lots of holes in it for the heat to escape through.

Always leave the tap open to allow excess liquid to escape. Liquids can retain heat within the farm.

Leave the lid open a couple of centimeters to allow hot air to escape as the worm farm warms up.

It’s good to spray the worm farm and ground around it with some cool water every day, morning and afternoon. Not enough to flood the farm, just to help cool through evaporation.

Crack open the lid a little to let hot air out.
Keep the lid open a couple of centimeters

Ice packs are great for cooling a worm farm. Your worms will congregate around them. I’ve found that placing the ice packs in the middle of the farm works better than placing them on the uppermost layer. That way, the worms congregate in the middle and bottom trays and the top tray provides an insulating layer until your worms are ready to return to it and start feeding again. If you don’t have ice packs, a bottle of frozen water will substitute. If you use an ice pack or bottle, wrap it in a covering such as reused plastic to help keep it clean and of course, clean the pack or bottle before you put it back into the freezer.

As a substitute for ice packs, you can freeze your vegetable scraps before they go into the worm farm. The ice in them will keep things cool. Freezing has another benefit too – freezing expands the water in its cells and bursts them. Once the food has thawed out and you put it into the worm farm, they will be able to eat it more easily.

Keep the tap open so that liquids can drain
Keep the tap open so that liquids can drain

Also, if you have a tower type worm farm, make sure that there is something in the bottom layer so that the worms can climb up should the tap become clogged and liquid accumulate. I’ve lost a batch of worms that way. Their instinct is to dive down in the heat and they can become trapped in the built up liquid and drown. Cleaning up a mass of drowned worms is not pleasant. It stinks!

A damp sack can help cool the worm farm
A damp sack can help cool the worm farm.

One other thing you can do is to cover the worm farm with a coarse fabric such as hessian or sack cloth. Keep dampening this throughout the day. and as breezes blow, evaporation will cool the worm farm in the same way that an evaporative cooler cools the air.


Keep them happy and they will breed well in the warm weather and reward you and your garden with a lot of extra love in return.

If you want to learn more about composting with worms, click here to be taken to our ‘Compost Worms‘ page.

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