There are many options for caring for your tower’s ecosystem over the winter, depending on your climate and desired level of involvement. Red Wigglers can tolerate near freezing temperatures, and the tower’s 8 inches of soil helps insulate their compost tube. You can remove the compost from the tube (where most of the worms will be) and transfer it to a well-drained hole in the ground covered with straw, mulch, or woody debris, and add some kitchen scraps.
If you live in an area with milder winters (Midwest) you can cover the tower with a transparent trash bag to help insulate the tower, or move the tower closer to a building, which holds heat.
If you want to grow over winter and have ample lighting indoors, transferring the tower indoors would be great, just don’t water it for a week before you move it and it will be much lighter.
We have more information on our Extended Growing Resource Page.