That is a New Zealand Purple Castor Bean plant. They don't overwinter where I live but they reseed everywhere in my yard. They only get around 12 to 15ft tall by the first frost in TN. They are not one of the Giants. I had one of the Zanzabars over 30ft a few years ago. I planted it in the house in a pot in November and planted it outside in the spring. I get them at least 25ft or more doing them this way. I would of had some that tall this year but my niece cut them down with the weedeater. I have at over 40 clumps of bananas in my yard.