Purple passion fruit is a woody, perennial vine that climbs. Its fruit is grown for the seedy pulp that is both sweet and tart in flavor. It is eaten fresh, used in smoothies or juices, or for making desserts. A subtropical fruit that can be grown between sea level and 1300 meters, but fruits better at the higher elevation end. Purple passion fruit flowers are self-compatible. Plants require an annual rainfall of 90 cm. They can be grown on many soil types but prefers sandy loam with a pH of 6.5 to 7.5. Good drainage is important. Regular watering will keep a vine flowering and fruiting almost continuously.
Purple Passionfruit is native to South America from southern Brazil southward to northern Argentina. It has been well established commercially in Brazil and is now grown in many areas of the subtropics or in the mid-elevation tropics worldwide. A related form, the more tropical Yellow Passionfruit, grown abundantly as a juice source, is considered a possible mutant of Purple Passionfruit.
Purple Passionfruits are a source of seedy pulp; eaten whole with the seeds or added to fruit salads. Strained fruit pulp is a beverage base often sweetened and diluted as a juice used alone or in fruit juice blends. Concentrated juice or syrup of Purple Passionfruit is used in desserts, candy, icings and meringues. The seeded pulp can be made into jellies or jams.
Purple Passionfruit is subtropical. Although it grows well in tropical lowlands, flowering and fruiting require tropical elevations of 700-1300 m (2,000-4,000 ft). At tropical elevations above 1700 m (5,000 ft) consider using the Sweet Granadilla, Passiflora ligularis, a species with excellent fruit qualities and adaptations to high elevation growing conditions. Yellow Passionfruit, Passiflora edulis f. flavicarpa, is better adapted to the hot humid tropical lowlands. Purple Passionfruit is best grown from fresh seed, as older seeds lose viability rapidly. Plant seeds 1.5-2.5 cm (0.5-1 in) deep in beds. Germination occurs normally in 10-20 days. Transplant 25 cm (10 in) tall seedlings to well-drained soils rich in organic matter. Allow full sun exposure; in very hot climates, provide partial shade. Strong trellis support is required for the vigorous vines. Regular watering and fertilizing promote continuous growth, flowering, and fruit set. Too-dry soil causes fruit shriveling and premature fruit drop. Purple Passionfruit also may be propagated by cuttings from healthy vines, using 3-4 nodes of matured wood, rooted under intermittent mist. Grafting Purple Passionfruit scions to Yellow Passionfruit rootstocks provides the grafted plants with the root disease and nematode resistance of the Yellow Passionfruit rootstock. Use knee-high seedlings of pencil-sized stem diameters for both stock and scion. Cleft, whip or side-wedge grafts may be used. Fruit set requires pollination. Purple Passionfruit normally is self-fertile; however, pollination occurs best in humid conditions. Pruning vines increases fruit production. During the dormant winter season cut out dead wood and unhealthy vines. Prune back vigorous vines to well-budded stems.
Harvesting and Seed Production
In seasonal climates, like Florida, USA, Purple Passionfruit flowers and sets fruit in early spring producing mature fruit from late May to early July. In less seasonal climates, flowering and fruiting are more continuous. Purple Passionfruits turn from green to deep purple quickly at maturity. Soon after color change the ripe fruits fall off the vines. Pick them after color change occurs or collect them daily from the ground.
Pests and Diseases
A wide array of plant pests attacks Purple Passion vines, especially in the tropics. Passion vine mite can defoliate plants in the dry season in some Hawaiian and Australian regions. Stinkbugs suck juices from tender shoots. Leaf beetles and weevils chew foliage. Cutworms behead seedlings in nurseries. Scale insects attack vines and petioles causing vine dieback. Fruit fly damage to young fruit occurs in some regions. Watch for brown spot, Septoria spot, and base rot fruit diseases. Septoria spots on fruits are smaller and more numerous than brown spot infestations. The fungus is spread by rain and overhead irrigation systems. Effective control of rootknot nematodes, a serious pest of Purple Passionfruit, is obtained by grafting to Yellow Passion rootstocks.
Cooking and Nutrition
Clean, washed and dried fruits will store for 2-3 weeks in a cool place (10o C/50o F). Slightly shriveled fruit, a few days old, is sweetest.
Morton, J. 1987. Passionfruit. p. 320–328. In: Fruits of warm climates. Julia F. Morton, Miami, FL.