I checked my Sunset book to see what they said, the plant can be used
outside where it does freeze, but very lightly, like here. when we
get frost, it is the cold clear night kind, no real penetration. If
you keep the plant above 32F it should be fine.

I wondered if it was cold or long nights that triggered blooming, must
be day length. I have blossoms on a couple of mine already.

Yes, I believe that it is the length of the day. One of my coworkers
keeps a nicely sized specimin at work near a south-facing window, and being
an office, the temperatures are pretty constant all year - but it (and the
other plants) never fail to follow the seasons because of the light that
comes through the window.

steve