Because you have such a swing in your temps, you may first have to figure out where to put your worm bin before deciding what type to use. Worms prefer a pretty narrow temperature range for optimal functioning. Ideally, 60 to 80 degrees although you can fudge a few degrees either way before they slow down. Mine stay in my garage all year and my garage is heated in the winter to around 55 to 60 degrees.
