The only 'passionflower' I have grown is the native Maypop (Pasiflora incarnata), and that is in a bed in my yard, not a pot. Here in Georgia it is a wild plant that dies to the ground in winter, so it would not make a good subject for outdoor bonsai. I haven't tried overwintering any indoors, because, by October they are about 20 feet tall and all knotted together. Also it's leaves are about the size of your hand - too big for an easy bonsai.

Which cultivar were you thinking of trying? If the stem gets woody, and the leaves aren't too big, I'd say give it a try.

On second thought, heck...try anyway...you may wind up with something unexpectedly attractive, even if it doesn't fit the standard definition of 'Bonsai' (The Atlanta Botanical Garden has some gorgeous red passionflower (P. coccinea?)vines in their display)

yeah, I was thinking incense passion flower indoors, the leaves are big but I was thinking more long-term. It would be a breathtaking plant if I could train it for years into a large bonsai. But there are so many varities of passiflora that I am not familiar with all of them. There may be some with smaller leaves. The flowers of the incense just astound me, but I may settle for some smaller-leaved one with less attractive flowers.

I also have a passion vine that is in the process of being turned into a bonsai and i have been talking to a bonsai expert (bonsai9723 on youtube) and he said it would make a great bonsai. my vine is beginning to take the shape of a bonsai and starting to bloom, though it is not big and only has the trunk apout the size of my pinky finger i think it has great potential, i hope i helped as much as i could,
Nick

I am trying it with passiflora caerulea, so far so well. I am going to go imperial bonsai big with it and try the shape as natural as possible, just shaped so another plant can fit within it without being impacted by it. Kind of windswept. However it is real young now and my mind may change on it's shape as it grows. If it lives.

I am new to the art of bonsai, but I have read a lot about bonsai and i am applying my knowledge to it...

Here is a link that might be useful: how to get ex back