Do you have a spot outdoors where you can bury the pot just for the winter? If so, you could plant your basjoo inside a cheap black plastic nursery pot. That pot would then be planted inside a decorative pot for the growing season (i.e. pot-inside-a-pot).

When the cold weather rolls around, remove the black plastic pot and banana plant from the decorative pot and then bury the pot in the ground.

You can now over-winter your plant outdoors as you would any other inground basjoo in your zone.

Rokal,

Thanks so much for responding. Unfortunately, with the limited growing space I have, I wouldn't be able to bury the Basjoo for the winter.

Do you have a crawl space under your house? That is where I keep my bananas in the winter.