Hi - I have had 2 passifloras over the past 4 years and they have survived every winter until this past winter. One is a white flower and the other a purple flower. The white flower is caerulea and the purple flower is lavender lady. I had been training them up a large trellis which extends from the ground up to the bottom of my deck and further skyward up the side of my deck. They had reached approximately 15' high with extensions and flowers everywhere. I live on southern vancouver island and the winters are very mild here, usually we do not get freezing or snow. This past winter we had a few brief cold spells where it got to minus 1 or minus 2 farenheit, and I guess this is killed my passiflora because neither has bloomed yet.

My questions:

1) What temperature will kill this type of passiflora in winter?

2) If killed, is there any chance it will grow back again from the roots or should I just give up on these plants? If there is a chance it will grow back at what point will I know when to give up (ie - next Spring)?

3) Is there anything I can do to protect these plants over the winter if I want to leave them in the ground and trained through my trellis? I have read in your forum where alot of people bring them inside in the winter but I am wondering what I can do to protect them over winter if I want to leave them outside and planted in the ground.