Mine stay out all winter. A good percentage of my lilies do not go dormant, so I have no reason to pull them. But for people in colder zones.....according to my friend who was the farm manager for Strawn's Water Gardens, which is a z8, in a normal winter if they left the tubers out they'd lose 10%, a colder winter and they'd lose up to 25%. I've heard claims of unprotected tubers surviving z7, but it is certainly nothing I'd risk my stock to or recommend to my customers. Probably more fanciful thinking than anything.<g> You aren't considering leaving you out are you Frank?