We never use cold treatment with our trupet vine, that we sell. I get about 90-93% success rate with growing these from seeds. Here is a link that might be useful: Nipa Hut Gardens and Gifts

@Shad Burns I'm curious, where did you buy your seeds or vines from? I grow them too, and I'm always curious about the source of passiflora incarnata, when grown successfully in zone 5/6. Mine were selected from the wild, in Michigan, Indiana, and Ohio. I'm always interested in hardier strains. @Helene Albert I am in zone 5b, Chicago suburbs, literally a stone throws away from you. I grow passiflora incarnata successfully. I have fruit that's ready to harvest at end of August continuing through to October. It's truly a may sprouting perennial for me. If anyone is growing passiflora incarnata in zone 4/5/6a, please send me a message through Houzz by clicking my profile. I cannot send messages by default to most people, because messages are not enabled by default in Houzz until you go to your profile and enable them under "advanced settings." You should be able to send to me, however. I collect hardy passiflora incarnata. There is some genetic variation. Even the white version of P. incarnata aren't the same, with at least 5+ different strains floating around.

Hi, I'm in the Detroit area and it is a lovely plant, but if you plant it near a power pole, it may go crazy and take over, even in Michigan. Edison frowns upon it because it can be a problem. My mother was a farmer south of Cadillac, and she always said the same thing as Sunlicious - Never plant it near a house or a garden you want to keep tidy. You might end up pulling it off your porch roof and from everthing else near it. It will go everywhere, even down here it is hard to control if it likes a spot. Now, if you have something ugly you want covered, and don't need to worry about it going crazy, have at it! They do sell shorter less invasive varieties, but I'm never actually been able to keep one of them alive, and those have been planted far from anything we cared about.

My mother had this plant at her home and the suckers popped up everywhere and even came up through a freshly paved driveway. A few neighbors had them popping up in the lawns all over the place. The only way we got rid of the largest plant that had become a 6 foot high tree was to cut it down and drill holes through the trunk to create a bowl and we poured the salt that is used for snow and ice and let it soak in the truck and it slowly killed it. It's a horrible invasive plant that she not be sold at garden centres.