Planning the crop
Black passionfruit is widely adapted but requires a rich, well-drained soil and support – in the form of a trellis, pergola, arbour or fence, ideally about 2 m high. Passionfruit requires full sun to fruit reliably, although it tolerates occasional mild frosts.
How many to grow- The flowers are self-pollinating and one vine will supply most families. Vines start bearing within 12 months of planting: they flower in spring to produce a summer crop, then flower again in autumn for a winter crop.
Varieties- The most common species are black, or purple, passionfruit (Passiflora edulis), yellow passionfruit (P. edulis f. flavicarpa) and banana passionfruit (P. mollissima) (a weed in South Africa; do not grow). Other species that are widely grown in subtropical to tropical regions are: the Jamaican honeysuckle or water lemon (P. laurifolia), with bright goldenorange fruits; the sweet granadilla (P. ligularis), generally thought the finest passionfruit of all, with purple and white flowers and large orange fruits filled with exceptionally sweet and fragrant pulp; the giant granadilla (P. quadrangularis), with crimson flowers and melon-sized fruits that have fragrant sweet pink pulp; and the sweet calabash (P. maliformis), which closely resembles the sweet granadilla and has grape-flavoured pulp and fragrant purple and white flowers. Some selected varieties of grafted passionfruit include:
Panama Red- Large, oval, smooth skinned fruits; intensely flavoured pulp similar to black passionfruit, but needs warmer conditions. Panama Gold is similar but with golden skin.
Nelly Kelly- Hardy; large, smooth skinned, purple fruits; excellent quality.
Black Magic- Cold-tolerant; superior quality.
Ester- A hybrid, grown from slips.
Super Sweet AV1- Large, pink-skinned variety; heavy, regular bearer; good disease resistance.
Dig generous amounts of compost – and dolomite if soil is acid – into the soil before planting in spring. Mulch the plant well, but keep it away from the stem, and water in thoroughly. Help young vines to climb up their support by attaching with soft ties. Fertilise in spring, early and late summer, and mid-autumn with extra compost or a pelleted slow-release organic fertiliser. Also water regularly. Prune in spring every second year: progressively remove any branches below 60 cm to improve air circulation, and also thin out old branches. Different passionfruits are usually grafted onto yellow passionfruit rootstock, which is resistant to various root rots. These grafted vines generally live longer and are also more vigorous.
Pests and diseases
Root rots occur on ungrafted plants. Common problems are a leaf-spotting fungus and a virus that makes fruit ‘corky’.
Harvesting and storing
Harvest black passionfruit when fully sized and coloured – they are at their best when slightly wrinkled. The Panama varieties, however, are ripe when still smooth. The pulp can be extracted and frozen.