Banana plants need plenty of wrapping in winter to keep them warm. Without protection, the cold weather will decimate them and they'll have to grow from scratch in spring. A little extra effort will ensure thriving bananas that bring tropical cheer to your garden. It will die to the ground but will resprout from the roots(called a corm) in the spring and will grow bigger and faster next year. However, that is just depending on the species...there are several bananas that are rated down to zone 8a, but not all from what i understand. For more information you can refer this link.