My Ensete appears to have survived my mistreatment/testing of it having left it in the ground until Tuesday after Christmas. The photo shows that it has pushed 3/4″ of new growth since I cut it back and placed it in its corner in the basement. The NOAA weather station at PDX reported 17 freezing minimums to that date, eleven prior to December 20, ranging form 22º to 32º, nine of them below 30º, four below 25º. Over this period my local temperature, bizarrely, dropped to 30º, once, maybe. A second cold spell hit here from Dec. 20-27, again less severe than that at PDX, but closer. The Reed College weather station recorded five freezing minimums over this period, 32º on Dec. 12, 30º on Dec. 21, 28º on Dec. 24, 30º on Christmas and 27º on the 26th. Reed College is about 3/4 of a mile south of me on similar terrain with the same aspect. The freezing, cell shattering, of my plant’s leaves was very evident after this latest cold snap. During December’s first cold spell I was generally a degree or two warmer than the Reed station’s minimums. Over the second cold period my area was more consistent with the PDX temperatures, but still on the warm side. So, yay! My red Ensete has indeed survived 5 significant freezing minimum temperatures, as low as 27º! Those of you who dig yours in October take note, your gardens can benefit from these statuesque specimen much later into the local winter season here…and, return to their garden locations earlier as well.
How do I know its alive? Bananas are all monocots and their dividing/growing meristematic bud is on top of the rhizome, just above ground. If this bud freezes your plant cannot grow any longer. As I pointed out, mine has been growing, slowly, in my cool basement. Would it have made it down to one night at 25º…I don’t know. It is also difficult to say how many more days it could have survived down into this minimum range. Remember that it isn’t just the absolute minimum temperature we need to worry about, but the duration as well. Three of the coldest days had very cold highs as well just making it above freezing allowing the cold to penetrate tissue more deeply.