My garage is insulated and also stays around 40 degrees all winter. All those potted day lilies I mentioned in a previous post initially started in my garage in the late fall - where they all came down with Rust and spider mites. That is why I threw them all outside and protected them well.
This might not happen to you, but this was an expensive learning experience for me.
I do wonder if I had tipped those pots on their side in the spring ( which is a tip I picked up later) if they might have survived. Granted, in. A greenhouse or other protected spot, the water can be controlled.
I have also overwintered many other types of plants in my garage, and never had a problem. That year I did.~ Jan
