Brrr! Zones 6/7 sounds mighty cold in winter to this soft UK inhabitant (no wonder I see television images of you lot wearing those long coats!).

You could try the passiflora forum, they're pretty good, in addition try this online resource "Passiflora Online",
http://www.passionflow.co.uk/

Also try the link...
Have fun!

Here is a link that might be useful: Passiflora Society International

Have faith! Since most of the Passiflora breeding has taken place in Great Britain, you should be able to grow many.

The best site is Myles Irvine's site, www.passiflora.com.uk(I think) It's easy to find on Google. He's one of the three main breeders, and his site is pure information, no sales or contributions required.

I just saw that someone was growing P.ligularis in zone 6, and that's a fruiting one! And I recall looking up another that ONLY will grow where it's cool.

Myles says:

"Most Passion flowers are vines thought to have originated in either the cooler mountains or the much hotter tropical rain forest."

You may be able to grow Passifloras the rest of us can't.

I'll go through my notes and find out which one likes it cool. Like Brugmansia sanguinea, it HATES hot weather.

myartichokeheart thanks. ( I am planting seed of the Sang..)

I'm in Michigan, zone 6, and I've got incarnata and an incarnata/incense cross growing outside (with minimal protection). In addition I have Vitifolia, Incense, Capsularis, Carulea, Lavender Lady and a couple of unknowns growing in pots that I take in each winter (most for 5+ years now)

Oxmyx, you may find growing from seed frustrating as many take years to bloom from seed and some of them reportedly won't even bloom if grown from seed (Which I thought was a foolish thing once upon a time, but a stubborn 5 year old plant I grew from seed still has yet to produce even a single bud)

~Chills

hmmm conflicting report, I will have to look into that
growing from seed.........