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I just planted some passion fruit vines (from the seeds in the fruit) this winter. I have 5-8 vines and they are all growing vigorously. They have been blooming for about 2 months now but the blooms seem to fall off and no fruit ever forms. Will it take a few years before it actually produces fruit? Or does it need something that it isn't getting? I fertilize it with miracle grow every 2 weeks and osmocote once every 4-6 weeks. The vines are in large ceramic pots with good drainage on either side of an arbor.
If they are blooming, but not producing fruit, you may need to hand pollinate. Use pollen from a different vine to pollinate the flowers. If it is successful, the flower will shrivel but not fall off the vine. Within a week you should begin to see the fruit developing. Most fruit takes 2 to 3 months to ripen and fall from the vine. If you want the fruit to make juice, let them ripen indoors for a few days. If you want them for seeds, let them shrivel and ripen for several weeks before removing the seeds.
You didn't mention which variety you are growing. Most take 2 years to produce flowers when grown from seed, but once they start flowering, they should be able to produce fruit.
Noel's Special should be self-fertile, but if there are no pollinating insects around, you will still need to hand pollinate. The seedlings may or may not be self-fertile, and could just be too young to set fruit. Just get some pollen on the end of your finger and apply it to the stigmas. You can also pluck off an anther coated with pollen, and press it against the stigmas on another flower.
Here is a pic of a Blue-Eyed Susan passie flower that has the anthers and stigma labeled. The anthers carry the pollen (looks like yellow dust). To pollinate, you can put some pollen on your finger and touch the stigma, or use a paint brush, or just pick an anther, and dust the stigma with that. The pollen can remain viable on the picked anthers for several days (longer if properly dried), so if you don't have 2 blooming at the same time, you can pick the anthers and use them the next day or 2.
Hybrids and regular species can also be bud pollinated. This is the only way most hybrids will form fruit. To bud pollinate, you find a bud that is ready to open in the next day or 2, and peel back the petals. This will expose the tips of the stigma, and you can pollinate them, and close everything back up (see next pic).
Last summer I got about 15 fruits on my Incense--I think most were from my hand pollinations (x caerulea). All of the fruit had viable seeds, although some were larger than others, and some were flat (non-viable). The number of seeds ranged from 20 to 40. I planted 30 of the seeds earlier this spring, and only 6 germinated. I have 2 vigorous plants from those 6. I just planted another 70 seeds a week ago, and so far 5 have sprouted.
So far this summer I have only 2 fruits on my Incense (both x caerulea). I am beginning to think that the bud pollination has to be done more than 24 hours before the flower opens for it to take. Here's a pic: