So this wasn't the coldest winter for Cincinnati, but I have a surprise to report. Canna flaccida that I grew from BX seed survived its first winter outdoors, in pots, ABOVE ground. I had so many extra seeds that I was willing to sacrifice these to test their hardiness. Imagine my surprise! Another surprise is that my tropical Canna hybrids that grew from self-sown seeds are coming back for their 2nd year in the ground next to the house. They're literally inches away from the house, so obviously getting enough warmth to enable them to over winter. (The parent plants died their first winter, and they were located 2 feet from the house.) Maybe this year they'll be big enough to bloom? Thanks Dr. Jim for donating these Bandana of the Everglades seeds! :-)