See link below for info.
If your seed is too old and too dry it may never come up. Be patient and hope..
Myles

Here is a link that might be useful: Passiflora seed germination

I soak mine for two or so days, changing the water 2-3 times. I tried soaking in orange juice (most seeds damped off, even with rinsing) and lemon juice (all came up, but not faster or better than with just plain old H2O.

I planted about 3/4ths inch deep and I had plants in about 2-3 weeks (incarnata and edulis done this way).

Edulis took longer, about a month or so.

I do the same thing with Morning glory seeds, soaking for half the time as passionflower seeds and I've had plants over an inch tall in just 5 days (including soaking day).

~Chills

I've had some come up after a year & a half of sitting in the dirt doing nothing.. ANd some come up in a week.

If you're really lucky like I often am, by the time they sprout you've lost the tag so you have no idea what just sprouted. It's like a lottery.

I recently started 3 incarnata seeds and 3 alata seeds. I soaked them for 3 days in fresh lime juice mixed with orange juice (because that was what I had handy, they were really smelly after.) I kept them in the juice on the heat mat. Then rinsed and soaked for 3 days in H20 (changed the water daily and kept on heat mat). Then planted in peat and on heatmat in little greenhouse thingy. These were my first of these varieties of passiflora seeds, so I didn't expect much.
The incarnata ~ 1 germinated after 7 days. 2 still haven't came up.
The alata~ 1 germinated after 15 days, 2 still not up.
Not sure if it matters what you soak them in ,
probably just the soaking in something and the heat help.

I have started Passiflora caerulea, mollisma, incarnata, foetida, & edulis in peat with the baggie method. Just stick them in moist peat in a warm place. I did not pre-treat any of them or give them light & had good germination results. Mine germinated in about a month.