Poor frozen worms!
Last Spring, I started a Worm Factory at my daughter's preschool. During the warmer months, I went by every week or so and took the kids in groups to check the worms, feed the worms, talk about vermicomposting, etc. They're having a lot of fun with it, but the worm box management is all on me - there are some teachers who like the box, but they are intimidated about how to care for the worms, etc, and they're busy with their regular curriculum already. So, that's fine, I intended to keep it a very low-maintenance program for them. I want to show people that having a worm box doesn't have to be a lot of work, because much as *I* love my worms and check in on them all the time, I know most people don't. I want to show those people (and the kids!) that worms can be fun and easy.
When it got colder and rainy (and my own schedule got busier) I stopped being able to stop by as much. I peek into the box now and again and it's been humming along just fine (lots of cocoons, lots of clusters of worms all over) and one of the teachers puts food in now and again.
Well, the last several weeks were very cold - dropping to the 20s and below at night, staying under 40 during the days - and when I checked the box yesterday, the poor worms were clustered up in the 2nd and 3rd levels, with the top level frozen through and frozen VC (crystals throughout, not a solid chunk) surrounding the worm cluster. I'm sure some were lost, but for now at least, the cluster seems to have worked to keep most of them alive.
My question is - can anyone suggest an easy, cheap low- or no-maintenance idea for keeping the worm box from freezing through? They won't take it inside the building (there are some serious worm-phobic teachers!) and again, I'm trying to keep this an easy project for them. Do you think just covering the thing with a tarp during freezing weather would be enough?