It depends on what kind of passiflora you have. There are some like incarnata that can take more cold than others. If it is in a pot in is more likely to freeze than if it is in the ground with some protection. If you scratch the stem (if there is any) and there is green, then you have some hope. Some types will freeze all the way to the ground and come back in the spring. I would bring the pot in and give it a grow light and water very minimally and see what happens. The only other thing to do is to leave where it is and wait till spring :) I am impatient so i'd probably bring it in ;P

If the roots have frozen solid, its probably toast. 'Lavender Lady' can take brief cold below freezing, but not if the roots freeze. Even incarnata will not survive having the roots frozen solid. You could try bringing it in and hope I'm wrong.

~kiwinut

yup bring it in- there may be a chance not all the roots have frozen.. Just keep it a little moist & hope.

My lavendar lady is flowering indoors right now. It has lost about 2/3rds of its leaves (which is normal) and it has about 15 more buds to open..

~Chills