I've read that most pitchers can tolerate brief periods of freezing, but how long is "brief?" In the spirit of natural dormancy, I leave my s. wrigeleya, s. purpurea, s. flava and s. psittacina outside until it gets below freezing (normally in January here in Atlanta). I then put them in the fridge only for the sub-freezing days, then put them back outside.
Sadly, last weekend I was away and, lo and behold, Atlanta hit 7 F on Sunday night. I returned today and the soil was still frozen. The weather is warmer now and the soil has thawed, but the leavers are wilted and the flowers stalkes (which started to emerge in November) are dead.
So, my question is, how long is too long for the rhizomes to be frozen and live? I suspect s. purpurea will be fine, but I'm not so sure about the others.
Thanks in advance!