After reading the posts by Lilth concerning the cold tolerance of the AeAe, I thought I should relay my experiences last year in south GA. Last year our low was 19.8 on December 6 (this is measured by an official monitoring station for the state of Georgia). We also had 6 additional nights of 25 degrees or below and an additional 19 nights of 32 degrees or below (for a total 26 nights of freezing or below freezing temps).
I had an AeAe growing in the ground completely unprotected. The low temperature measured at the house was 23 degrees. (I usually am about 3-4 degrees warmer than the location mentioned above.)
Remember the AeAe was completely unprotected, no wrapping of the stem, no light bulbs, etc. This spring when it started to warm up I was not sure what to expect but after the last few weeks, I think it is safe to say it survived the winter. {We had our last freeze (26 degrees) on April 8th.} Here are a few pictures taken this afternoon.
It has actually produced a few pups already (the biggest one was removed and potted up a week ago). Here is a picture of the biggest of the 3 pups still attached to mama.
Obviously this is not what I expected to happen and the plant does get a little help from the canopy of the large live oak that it is planted under, but it sure makes you think about what we "know" about cold tolerance of certain bananas. I wonder if it might actually bloom this year?
Based on the high price and low availability of AeAe pups, I would not suggest this as a method for overwintering your plant but I really had no choice based on the height of the pseudostem (93" at present).