Zone-pushing--no winter protection in Zone 6?
I know the "correct" answer to my following question, but I'm not looking for the "correct" answer. I'd like to hear from those of you who have tried the "incorrect" method.
How successful have those of you in Zone 6 (midwest specifically) been at leaving your canna in the ground all winter and seeing them bloom/multiply the next growing season?
Some years ago a local woman told me she had planted canna on the south side of her house 10-15 years earlier, had never lifted them for the winter, and they not only had survived every year, but had thrived to the extent that she was always giving away the extra canna every year.
I didn't have the south side of my house available, so I planted a few canna next to the west side of the garage. For about 5 years I had some canna blooming there even though I never lifted them in the winter. (Leaves from the neighboring oak trees would fall on that bed.) I wouldn't say my canna thrived there, but there were always at least several canna that would bloom.
Then I wanted to redesign the west side of the garage, which meant I was left holding 5-6 rhizomes (is that what they are called?). Despairing of finding a place to put them, I dumped them in the ground by the wire fence back by the alley. My neighbor's oak tree always sheds a ton of leaves back there--a real pain to rake up every spring, but evidently enough protection for the canna because they grew back for several years with no other winter protection or care. However, last year I tried a lawn service (I'd always done my own lawn care before) and had them blow away about half the leaves back there along the fence so that there wouldn't be such a big raking job this spring. That worked out fine, but none of the canna grew back at all.
What do you think--was it just luck that the canna kept coming back by my fence for several years, or was that extra pile of oak leaves just enough winter protection to keep them alive for those years?
Have you managed to keep canna alive and producing without digging them up and storing them each winter? I'd be curious about what kind of luck you had if you did.