I have one of these tree mallows that I grew from seed this spring. As it is already three and a half feet tall, I would rather not bring it indoors unless I have to. Also, since the leaves grow straight out from the trunk, it would be difficult to take cuttings. Most sites vaguely call the plant half-hardy, though, so I suspect it won't survive a Zone 5 winter. Can anybody tell me for sure? Thanks!