Passiflora pollination compatibility

Moin everyone.

My passiflora incarnata produced hundreds of flowers this year, but only a handful of them actually grew to become fruit. Self-fertility seems to be rather rare and I have tried both the natural way via bees and pollinating them by hand

Now I am thinking about introducing a second passiflora to ensure pollination. And I am wondering if a passiflora caerulea would do the trick since it is also quite frost tolerant and blooms over a long period of time.

Has anyone here tried to combine p. incarnata and p. caerulea before?

 

I think it may well pollenate the incarnata but will probably swamp it if you plant it too close.
I find if you prune you tend to slow flowering.