Tony, I'm confused. You first write:
it is hardy in zone 7b...occasional temp drops to 0F
and then you close by writing:
It is certainly not hardy outdoors even in the colder parts of zone 7
If it is "hardy" in either part of zone 7, what does it look like
after a typical zone 7 winter? You are saying that the trunk will
survive in zone 7 without protection?!? I wonder if we're talking
about the same plant <g>