All mine are still outside.
I've been doing some research into the Ensete venricosum tribe, and and found some very interesting stuff. I'm going to write an article on the growing conditions they get in the indigenous areas, and you would be quite surprised. Unfortunately I'm having to do training courses at the moment, as well as getting all my normal days work done, so just not had time to write it so far
I'll say a brief bit about what I have found here.
Ensete ventricosum, The Abyssinian Banana comes from the highlands of Ethiopia. around 7 degrees north of the equator, so is a tropical plant. The wild green form grown from seed is the least hardy of the Ensete Ventricosum tribe, growing to an Altitude of 1600m This equates to temps between 10 and 30C..... seems to make a mockery of our temperatures for sprouting the seed
The Ethiopians use the corm as food, so over the centuries have bred more cold tolerant cultivars that grow higher up into the mountains. Unfortunately all the culivars we have are named after the European discoverers, rather than the Abyssinian cultivar name.... Shame really otherwise we would know exactly how hardy they are. Some cultivars have been bred to grow up to 3000m which is nearly double the altitude of the wild green one.
We all know that the Standard (wild, seed grown) ventricosum is less hardy than Maurlii, Mondbeliardi, Hiniba, Tandarra Red etc, this is probably due to them being the bred culivars for growing up in the high mountains. My small Montbeliardi survived -4C under cover kept bone dry still in its pot last winter.
Addis Ababa is at 2,400 m and the Esnete grow up to and beyond that height.
Here is the climate for Addis. Note the warmest average night temps are 10C with the coldest average nights 5C Record lowest 0C Also note the deluge summer and drier winter with low humidity. Seems they can survive warm days with 9 hours tropical sun with temps dropping down to around 5C while being almost completely dry. This is the tip for overwintering here. So if stored in a garage or shed dry, temps of 15 or 20C will not cause them to croak.
- Addis Ababa Climate.jpg (42.61 KiB) Viewed 3449 times
Looking at that climate it is not surprising they do very well in our summer. but we have a major advantage over the Ethiopians, we have as much feed as it needs, where as they struggle. The time from a pup to harvest, just before flowering is 7 to 15 years depending on altitude..... can you imagine growing a crop for 15 years before you can eat it
(I would have dug them up but I'm out of Compost and Perlite 
)
leaving just the growing point and perhaps one more and just leave it then till Spring. But this last Winter I foolishly gave it water in very early Spring, and together with extremely low temps it just died. It had a big corm which had started to rot and I kept cutting away at it bit by bit, but rot kept setting in and it was smelly - until basically there was nothing left of it. I could have kicked myself after as I knew I shouldn't have watered it that early,and put it somewhere a little warmer. Why I watered it, I don't know, it was just an impulse thing. I'm potting mine up and putting it in the porch again this Winter, minus the water, and hope we have a milder Winter and it pulls through okay.(and everyone else's too 
