Ecology
Altitude and latitude do not appear to be a constraint other than through the temperatures associated with them. Purple passion fruit grows best in a subtropical climate, and the yellow passion fruit prefers a tropical climate with full-season warm days and nights. However, even yellow passion fruit can survive temperatures down to - 5°C. The purple passion fruit grows well at higher altitudes in the tropics and has the better flavour, whereas the yellow passion fruit grows better in the lowlands. Generally, annual rainfall should be at least 900 mm. Rainfall in Indian areas that grow passion fruit ranges from 1000 to 2500 mm/year. The species is shallow-rooted but withstands drought by defoliating. Passion fruit tolerates a wide variety of soils and grows best on well-drained sandy loams with a pH of 6.5 to 7.5. Passion fruit is moderately intolerant of shade, requires trees, brush, or fences for support, and benefits from but does not require soil disturbance for reproduction. Wild plants are found in broken forests, stream-bottom galleries, fencerows, abandoned farms, and neglected city lots. Young plants are eaten by livestock, so passion fruit is almost never found in moderate to heavily grazed areas. A large number of insects, nematodes, fungi, and viruses attack the species.