wispfox, I would agree that it might be too early for P. incarnata in many places. More importantly, you should be aware that not all strains of P. incarnata are equally hardy. It grows naturally from Florida to Southern Ohio, if I remember correctly, and the hardiness of a strain reflects its origin. The simplest solution is to get a sucker from someone who has been growing it in zone 6. It's not a plant I grow. I would recommend checking on the Passiflora forum for a zone 6 source. The forum is a bit sleepy lately, but it's still probably worth trying. I would recommend posting in the general discussion section, as the question of P. incarnata hardiness is an important one that should be raised periodically. Good luck. Here is a link that might be useful: Previous Passiflora forum post seeking a zone 5 plant

Wanted: Nandina domestica 'Purple (or Plum) Passion' and Hypericum androsaemum 'Albury Purple'. Much to trade: Boxwood 'Suffruticosa', light orange iris, light lilac iris, lambs ears,lemon balm, balsam and purple verbena seedlings (not sure how well they would travel), peachy daylily (solid), 2 different sedums with yellow flower, spiderwort 'Sweet Kate'. Tons of seeds. Trade list was not updated. Gardenbud

Crisann, I have Passiflora incarnata ALBA, which is the native white passion vine - email me if you're interested in a volunteer seedling - I think there are still some out in the flower bed. If you email me, REMIND ME of what you want, put GARDENWEB in the note or I won't have a clue what you want.

It may not be such a problem if you can get to all sides of where it is growing to control any spread. This earlier discussion might give you a better idea: Maypop aggressiveness.... Crossvine and coral honeysuckle are two commonly mentioned native alternatives that don't sucker any or as much. Some clematis can also do very well and get dense enough to cover things.