When the warmer months are over, the frosty days start to come, and for those of us that like to compost and cultivate worms know, we need to prepare for the winter freeze.
A standard earthworm has no issues over winter, but for red wigglers (composting worms), they need more care and attention to survive freezing temperatures. They are more important to look after because they can compost and reproduce at a much higher rate than standard earthworms, but are more fussy about cooler climates.
Worms don’t properly hibernate and nightcrawlers will burrow deep down in the soil to try to keep warm when its freezing temperatures, although red wigglers tend to stay near the surface. Because of this, they need to be protected in winter, and the best way to do it is insulating their living space.
They can survive temperatures as low as 40, as high as 85 very max, and thrive around 45 to 75 degrees Fahrenheit. The best way to be sure your red wigglers survive winter and preferably live at a consistent temperature is to not deliberately put them in your garden in the first place and keep them inside a worm farm.
I know this doesn’t help the ones that are already outdoors in your soil or compost pile but let me digress first and then I will explain what you can do for those outdoors that need to be protected. They are not the type of creatures that only last weeks or months, they can actually last years if looked after properly.
Cultivate your red wigglers in a worm farm
Keeping your worms in a worm farm is a much easier way to keep them alive because you can regulate their temperature more efficiently. When you put them outside in the soil or in a composting pile, there is an added chore to deal with. This is why I always recommend keeping them inside a farm.
Before thinking about warmth, it is best to set them up ready beforehand. Move all the worms and castings to the sides, add fresh scraps, shredded paper, and damp coconut choir (or other bedding) to the middle. Then level everything off, as this will get them prepared for the next step.
The easiest way to keep them alive in winter is by moving the worm farm to a place that is warm enough, somewhere indoors like a heated garage, spare room, utility room, etc. If you can’t do this and need to keep them outdoors, somewhere like a shed should be fine, as long as you insulate it properly.
If you keep them in a place that is still too cold, try to insulate the area as much as possible and also insulate the worm farm. You can insulate the inside by placing whole (damp) newspaper sheets on top of their food, followed by dry sheets, then dry leaves on top.
Then pack around the worm farm anything that can keep them insulated, like insulation foam, blankets, carpet, tarp, hay, straw, etc. This much insulation will give them the best chance of surviving. Placing them anywhere that has some shelter is 100 times better than leaving them outside.
Always remember to keep their air holes free when packing around it and the best way to monitor the temperature they are placed in is by using a thermometer.
How to protect the red wigglers already in your soil or compost
When worms reproduce, they do so with cocoons. These cocoons are able to sustain freezing temperatures, but unfortunately for the mature worms, they can’t. The best way to keep the mature ones alive in the soil or compost pile is by protecting the surface so underneath gets less cold.
You can insulate the soil and compost pile by adding a layer of mulch, something like woodchip and then covering it with a thick layer of tarp and/or insulation foam. It’s best to do this before winter properly sets in, so you give them time to get used to the temperature.
Even if your mature red wigglers don’t survive the winter (which can likely happen), their cocoons should be fine, as nature usually has a way of making sure creatures carry on existing. So the fact that each cocoon usually has multiple babies inside and you’ve helped as best as you can to keep them alive by insulating, you will have live worms when winter has finished and spring arrives.
In the wild worms lay their eggs and then have a very high chance of dying off over winter, allowing their eggs to hatch and carry on their species. But when you are manually cultivating worms, you have a chance to keep them alive for years.
We can do this by keeping their living space at a satisfactory temperature which allows them to thrive. Moving your worm farm to a warmer place or by insulating them as best as you can.