Passiflora edulis (purple) is self pollinating as opposed to P. edulis flavicarpa (yellow) that requires cross pollination to set fruit.
Passion fruit blooms in spring and early summer and again for a shorter period in fall and early winter. Manage these vines much like grape vines. Use a trellis and they pretty much take care of themselves. Pruning is okay because fruits set on new growth.
Harvest: The fruit will quickly turn from green to deep purple when ripe and then fall to the ground within a few days. They can either be picked when they change color or gathered from the ground each day. To store passion fruit, wash and dry them gently and place them in bags. They should last 2 to 3 weeks at 50° F. The fruit is sweetest when slightly shriveled. Both the fruit and the juice freeze well. The flavor of passion fruit blends well with citrus and many other fruit flavors, and is quickly appreciated by many people as they become familiar with it. Passion fruit vines grow best in sandy loam with a Ph around 6.5 to 7.5. Fertilize monthly during the growing season with a 13 - 13 - 13 or 6 - 6 - 6 ratio.
Here in South Florida Passion fruit vines benefit from organic materials added to the soil. A rich organic soil with plenty of worms is the idea. Be sure to provide extra water when your Passion vine is producing fruit. Mulching is also important to help keep nematodes away from the roots. Be sure that your soil is well drained because they don't like wet feet and can succumb to root diseases. Plant them on a mound to keep roots healthy during wet weather.
Be sure to prune your Passion Fruit Vine as soon as it is done fruiting. Pruning will keep it from forming a dense thick mess of tangled dead branches. If you don't prune your passionfruit you end up with a plant that has lots of problems with fungal diseases.
Other edible Passion Flower vines for South Florida
Giant Granadilla P. quadrangularis
Red Granadilla P. coccinea
Jamaican Yellow P. laurifolia
According to Bill Merrill: This is one of the finest tasting, conservative growing and beautiful passion vines on earth. In some areas it requires hand pollination but the fruit is worth it. Passion fruit seed can be difficult to germinate. You can speed things up by scarifying the seeds on a sheet of sand paper and then soaking in 140 f. degree water. Allow seeds to cool in water overnight and plant in the morning.