The Sweet Granadilla, or Passiflora lingularis, is a common species ranging from Central Mexico through Central America and Western South America, through Western Bolivia to South-central Peru. It is naturally adapted to high rainforests. Naturalized in diverse wet forest, rarely in drier areas. In its natural range, it is wild and cultivated at elevations of 3,000 to 8,850 feet (900-2,700 meters). At higher altitudes, it flourishes and blooms but will not fruit. In Hawaii, it finds sufficiently cool temperatures at 3,000 feet. Vining to 14 feet tall. It climbs by means of clinging tendrils and can be kept as an container plant. The long tendrils need lots of support for climbing. It may be grown as a houseplant in a sunny South-facing window.
In Hawaii, it is grown for its fruit and fragrant, ornamental flowers. The flowers are pendent, sweet in odor, usually 2 to a node, may be 4 inches across, on a 1 1/2 inch peduncle. The peduncle is bearing 3 leaflike, ovate-oblong and pointed bracts, 1 1/2 inch long and 1 inch wide, faintly toothed. The sepals are greenish-white; the petals pinkish white; the filaments, white, horizontally striped with purple-blue.
The fruit is broad-elliptic, 2 to 3 inches long, green with purple blush on sunny side. The rind is smooth, thin, hard and brittle externally, white and soft on the inside. The pulp is whitish-yellow or more or less orange, very juicy, sweet and slightly acidulate. Its leaves are broadly heart-shaped, pointed at the apex, 3 to 8 inches long, 2 to 6 inches wide, conspicuously veined, medium-green on the upper surface, pale-green with a bloom on the underside.
Pruning is a must to keep the vine healthy. Prune off less vigorous growth and occasionally prune back vigorous growth to promote flowering. When established, and without care, the passion fruit can easily overtake other garden plants, shading them from sun.
Hardiness zones 9-10, (-5°C/1°C, 25°F/35°F) in Winter. The vine is intolerant of heat. High temperatures and dry conditions should be avoided. It will do well over the Winter in Florida but declines with the onset of hot weather. Prefers sheltered conditions. Frost tender when young. Provide ideally a temperature of 7-25°C. It will do best in a loam based mix with a little peat moss. Thin, volcanic soils do not discourage the Sweet Granadilla.
You may need to water your plants on a daily basis during the hottest Summer months. During the Winter the roots should be kept moist, but as growth will be much slower you will probably only need to water once a week, depending on growing temperature. Fertilize at least once every two weeks in the growing season.
If their pot is too large or if they have an unrestricted root run then the whole plant will simply get bigger and bigger but it will refuse to flower and therefore produce the fruits. By limiting the pot size you are limiting the ability to grow and this is seen as a threat, so the natural mechanism is to produce seed for the next generation. A suitably sized pot for an adult plant would generally be of 12 inches in diameter.