I can't answer your question, but since you're in NoVA, do you know there's a place that sells passion fruit vines (the fruiting kind) in Arlington/Crystal City?

It's called Nature By Design and it's tucked away on some weird little dead end street near National Airport.

I bought a few plants from them a couple years ago and they are going strong now. One word of warning - - - the original plants send up new shoots EVERYWHERE. All season long I pull up volunteers from near and far away from the original plants.

Here is a link that might be useful: Nature By Design