Gabe15

It's gonna be a squeeze, but I would look at 'Dwarf Orinoco', they are hardy and small plants, the fruit quality is not the most preferred but they can be nice and any homegrown bananas will be better than none.

You can start it outside in a large container this spring, and then maybe plant it in the ground in the greenhouse towards the end of summer to overwinter there, and continue growth the next year, you could also just put it straight into the greenhouse but it won't get full size in one season anyway so you could use the greenhouse space for something else over the first summer.

The next challenge will be temperature control. The optimum would be to never let it get below 60°F for continuous growth, but that can be difficult with a simple greenhouse sometimes. The next reasonable threshold would be to not let it get below 35-40°F, at that temperature the plant will not be growing, but there will also be no damage, it would just hold on until temperatures warm again. At the very least, you should avoid any frost or freezing, as although the plants can survive, it dramatically reduces the changes of fruiting and can easily stunt the plant as it will start to cause damage, and in a sub-optimum environment, you really want to avoid that.

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Growing bananas in Colorado, Washington, Hawaii since 2004. Commercial banana farmer, 200+ varieties.