JennyC wrote:

"Janna" wrote
I have produced 2 passionflower climbers from seed this year and
they are
romped away to at least 8 feet although they haven't flowered yet.

They must have been really close. That is flowering size.

If they are 'ordinary' Caerulea type passionflowers, they will
probably be ok outside.
Leave the top growth in place. You can always tidy it up next spring
before it starts growing again.

You might want to protect the roots with some form of insulation, like
leaves, straw, or fleece. Fleece lets does not cause damp to build up
like bubble wrap will.

Assuming they are one of the more hardy sorts. I'd go for a bit of straw
over the roots and maybe some fleece or old net curtain over them to stop
the worst of the frost. I will freely admit that mine have to fight for
their survival unprotected in the unheated greenhouse and always get back
to growing on the roof by midsummer. The only benefit they get there is
dry soil.

Most times you will get away without doing anything at all, but if it is a
*really* hard winter...

Something to keep the soil near the roots dry and warm will help. Any
mulch will do.
But don't obstruct air flow with polythene or the moulds will have them.

Regards,
Martin Brown