mrbungalow

Frank: I understand the dilemma a little too well. As I stated earlier I would discourage anyone trying to store the corm of Musa basjoo or other temperate species in the basement. The basement of a house is relatively warm. Even at 50 degrees the Basjoo will be fit for fight and want to start growing.

I also understand your concern with the arctic blasts and prolonged subfreezing temperatures. But if you insulate and mulch enough, the inside of your wrapped structure will absorb heat/radiation from the earth and stay at about 32 degrees F or just above, wich is perfect for musa basjoo. I am sure a physics-teacher can explain the U-values of insulation better than me! If you really want to be sure they don't freeze, wrap heating-cables around the trunks, set to be turned on at a few degres above freezing.

I am not guaranteeing your basjoo will survive outside, but I think it's your best bet. I wouldn't be saying all this if I didn't think they would make it. I have heard of and seen examples of success in Chicago and Canada. Also, this is your only chance to get a truly large plant next summer. If you have a pup or two, why don't you take these inside as insurance?

And yes, the climate here is pretty temperate. I think Bergen is the warmest place in the world at this latitude (we are on the same latitude as the south tip of Greenland and Alaska). Still, it's no tropical paradise since it rains like there's no tomorrow here. Apart from Bananas, Windmill-palms, monkey puzzles, Gunnera manicata, and Cordylines thrive here. Bergen is also known as the Rhododendron capitol in Scandinavia.
We are not so battered by the Atlantic as you may think, that's because the coastline is uneven and has many islands, fjords, and mountains wich take the worst beating. Here today there's no wind but plenty of rain!

__________________