Passion fruit vines are vigorous, fast-growing climbers that can grow 15 to 20 feet every year, although they usually live for 5 to 7 years. The passion fruit vine grows 2- to 3-inch-wide, greenish-white flowers that sprout purple or yellow fruits. The passion fruits are 1-½ to 3 inches wide, round or oval, with a smooth, waxy outer rind. Growing passion fruit vines from seed is not difficult. Although passion fruit seeds can be stored, aim for planting the seeds right after removing them from the fruit for a faster germination time of 10 to 20 days.
Remove the seeds from the passion fruit, place them into a strainer and rinse them well with cold water to remove all the fruit flesh.
Fill a seed tray with a 3-inch layer of all-purpose, well-draining potting soil. Make sure the seed tray has sufficient drainage holes in the bottom.
Plant the passion fruit seeds ½- to 1-inch deep into the soil. Water the seed tray daily to keep it moist at all times, but ensure that the water drains freely from the soil. Place the seed tray in full to partial sunlight.
Transplant the strongest plants outdoors when they reach 10 inches in height. Select a planting site with good soil drainage, in full sun and next to a tall, sturdy fence or trellis.
Work organic compost or aged manure into the soil before transplanting the vine. Spread a 2- to 3-inch layer of organic mulch on the ground around the newly transplanted passion fruit vine.
Water the passion fruit vine deeply twice per week to supplement rainfall throughout the growing season. Water the vine daily during times of extreme dry heat.
Feed the passion vine a lower-nitrogen fertilizer, such as a 10-5-20 NPK (Nitrogen-Phosphorous-Potassium) fertilizer. Feed the passion fruit vine four times each year, at the beginning of the growing season, in early summer, in mid- to late summer and in mid- to late autumn. Follow the manufacturer's instructions for dosage.
Prune back vigorous new growth on the vine once each year and remove all weak growth. Prune in early spring if you have cooler winters, or right after the fruit harvest if you have warm winters.