We've been flirting with 80 F here in Washington for the last few days and we are predicted to hit it a couple of times early next week. As a grower of gaudy tropical plants, this is a great thing for me. The season is never long enough and while I appreciate the cool temperatures, a little heat will help these guys along. They seem to appreciate the heavy dews of fall, but not so much the low humidity in the afternoons.
The banana is Musa 'Basjooo' and it is completely hardy here and theoretically a bit farther north (USDA Zone 6). Hedychium 'Dr. Moy', in the bottom right is a solid Zone 7 plant, it has been in the garden for two years. Last year was, of course, a very mild winter, but the year before had some tricky cold in the spring that was a good test for Zone 7. The real question mark is the huge Brugmansia 'Charles Grimaldi'. It has overwintered for friends in this area and I am testing it this year. My gut feeling is that it will be one of those plants that technically lives through the winter, but will likely be killed back so far that.....well, we'll see.