“We have an unheated building to start our worms in. How cold can the worms get before there is a problem?” ~ Linda Harness
Different worms are tolerable of different temperature ranges.
For a cold place it is usually the two common composting worms which are ideal to use in a wormery system.
In most cold cases, they can survive through the low temperatures and will only work at a slower rate. Once the temperature goes back up to the ideal range, the activity will resume its normal pace. The only danger with low temperatures is when it reaches freezing point, and this is what you need to avoid.
Worms need to be constantly moist to help with its breathing through the skin. Once it reaches freezing point, not only are you freezing the worms but it also freezes the water around them essentially suffocating them.
I had mentioned many different ways you can keep your wormery warm in previous newsletters which does not involve buying expensive heaters and heating systems. One of the ways is simply adding a thick pile of straw over the layer and side of the system insulating the worms and its environment.
If that doesn’t work, do check our previous newsletters!