Most of mine are growing in pots along a trellis. I think they would cover an oblisk much quicker than an arbor, especially if they can't grow year round. (I'm not sure what zone you are in) I've bought nice plants from Kartuz but they are very small. I bought two huge passiflora vines from Caldwell Nursery in Texas. They got a bit banged up during shipping but recovered beautifully and are huge. There are a number of sellers on eBay that I've bought nice PF vines from. Impower56 and Georgiavines are two that come to mind right now.
Karyn

Maypops aren't "yellow passion flowers." Maypops are p. incarnata, which tend to be lavendar to purpleish in color. The species commonly called "yellow passion flower" is p. lutea. I've never grown lutea, but one nurseryman told me that lutea tends to be a dwarf plant, at least when compared to other passi species, and won't grow to more than 5 feet. I do have p. affinis, which is closely related and has a similar appearance. It is growing well, but still young. I have no idea what size it'll get to eventually, but should find out next year. I'm told it will easily cover a fence.

In any event, lutea and incarnata will survive your winters easily and should regrow from the roots in the spring. Affinis is iffy. Affinis and lutea both produce smaller, more demure flowers. Incarnata's are much more showy, and incarnata fruit are edible. Incarnata is also easier to find in nurseries and online because it is more showy. And if you want them to grow over an arbor or up and obelisk, remember that the larger the pot you put them in, the better. All three serve as host plants for the Gulf fritilary butterfly larvae.

I didn't say anything about a "yellow Maypop" and thought maybe it was some variety I didn't know about. lol The flowers of my Lutea are fairly small and kind of trumpet shaped, not nearly as showy as most passion flowers. The vine itself grows like crazy and is very easy to propagate from cuttings. I've always put it in the greenhouse over the winter and have no idea if the roots would survive our winters or not.
Karyn

Good Grief!

Thank you so much for correcting me! I don't know what I was thinking! I really want maypop (not yellow)... Do you guys think it will do better on a oblisk or an arbor?

Elaine

Elaine I think it would cover an oblisk quicker, depending on the size. I have some other types of vines covering an 6' oblisk. I don't know how tall a structure you are talking about.
Karyn