Answer: If your potted plant is not exposed to temperatures below freezing for more than a few hours, it will survive fine outdoors. Frosts will damage the leaves, while a hard and or lengthy freeze will kill the stalks or trunks. It would be better if it were in the soil where even if the top froze to the ground, the base would probably resprout the following year. Containers tend to freeze more easily, killing the base of the plant...thus no resprouting.
Your safest bet would be to bring it indoors. A possible alternative would be to sink the pot in the ground in a very protected location such as beneath the eaves of a home. A plastic sheet could be attached to the eaves, draped down around the plant and a heat source such as lights provided during cold weather.
Good luck with your banana!
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