Mptclinics

Hi all, I have just spent the last 2 hours researching my banana plants, and found NO help. However, in doing so, I stumbled upon this site, so I am hopeful I might find answers here.....

I live in central Illinois, which most maps consider right on the border of zone 5-6. I purchased 2 tiny little Dwarf Cavendish bananas in 4 inch pots 3 years ago. I replanted into bigger pots each year, adding fresh compost, peat, etc. The first year, I keep them strictly indoors. The last 2 summers, I put them outside in a mostly-sunny area. Their growth exploded, and they are gorgeous, vibrant, and seemingly healthy. Each has produced 2-3 pups, which I have let grow.

I have several questions.....

First, I purchased from a discount garden place, under the advertisement that these were "cold hardy" and fruited easily. After 3 years, I am wondering. Just how cold hardy, and should I expect fruit? Although I like them, they are quite large for our setup and a lot of work if they won't fruit, which was our intended goal.

Second, we have run out of room in the house. They have outgrown my windows. So, we are planning to put them in our new geothermal-climate-controlled greenhouse (aka walipini or pit greenhouse) once finished (just a couple more weeks hopefully!) we anticipate the temperatures should never get lower than about 40 in the coldest of winter. Will they still thrive in that?

Third, just out of curiosity, what are the chances I could plant them in the ground outside and just cut back and heavily mulch the pseudostems like I've read is recommended is some temperate zones? They do so well 5-6 months of the year outside. It would be awesome to have them out there year round and not worry about it.

Any advice would be greatly appreciated! I uploaded a photo of one of my plants for reference, but can't figure out how to get it copied here. It's in my photo gallery if interested (I think). Thanks in advance!