There are over 50 varieties of passionfruit vine including Banana, Hawaiian, Norfolk Island, Yellow Giant, Panama Gold, Panama Red and Nellie Kelly. Cultivars can differ in cold tolerance, so always check the label before buying. The kind you’ll most commonly find in Aussie backyards is the Nellie Kelly – a cultivar that has been bred to withstand cooler temperatures and resist pests and diseases. In more tropical regions, Panamas grow best.
Passionfruit vines are versatile but are best suited to subtropical and temperate climates, provided there is protection from frost when young.
Position your passionfruit vine in full sun with protection from strong winds. In colder climates, choose a spot in front of north facing wall to utilise to radiated heat.
Passionfruit vines grow extensive root systems so ensure the spot you choose to plant has plenty of space, free from weeds, competing plants and grass. They will also spread up to 10 metres squared so choose or build a structure that can accomodate it. Passionfruit vines can be trained to grow along your fence, on a trellis or over an arbour, just install some wire or mesh to support its tendrils.
The best soil for passionfruit vines is rich in organic matter and well-drained with a pH of 5.5 to 6.5.
The best time to plant a passionfruit vine is in the spring season. Before planting, prepare your soil by incorporating compost and chicken manure to an area around one to two metres wide. Dig a hole twice as wide and just as deep as the root ball, gently tease the roots, plant the vine and water well. Mulch around the base with sugarcane, bark chips or pea straw, but don’t let it build up around the stem.
Passionfruit vines can also be grown in large pots as long as they have an adequate support structure.
Passionfruit vines require regular watering, especially when the vine is young and when it’s flowering and fruiting. Water deeply a couple of times a week, depending on weather conditions and climate. Remember to spread your watering over the entire root system, not just around the stem of the vine.
Feed your passionfruit vine with well-watered-in citrus food or a chicken manure twice a year, in spring and autumn. Ensure you spread the fertiliser over the entire root system. Avoid over-feeding or using fertilisers that are high in nitrogen, this will encourage leaf growth at the expense of flowers and fruits.
Flowers usually appear in mid-spring before fruiting in early summer. Your first fruit will appear around six to eight months after planting but have patience – the best crop will come in around 18 months. Passionfruits need to fully ripen on the vine and will drop off when they’re ready to eat. They can also be picked off the vine when their colour is fully developed and come away from the vine easily.
The best time to prune a passionfruit vine is in late winter or early spring. Cutting the vine back by about a third will encourage vigorous growth and more fruit.
The passionfruit vine can be propagated from cuttings but is best grown from seed.
Not fruiting: A common complaint of passionfruit growers is a lack of fruit. There are a number of factors that could be to blame, but poor pollination is the most common. The essential work of bees can be impacted by changes in weather such as consistent, heavy rain, and fluctuating temperatures. Over-fertilization can also cause your vine to grow but without flowers and fruit.
Fruit dropping: If your passionfruit is fruiting but the goods are dropping off the vine, it could be due to irregular watering, fungal diseases or fruit flies.
Yellow leaves: Wondering why your passionfruit leaves are going yellow? The most common cause is woodiness virus, but it could also be down to magnesium or nitrogen deficiency, or “winter yellows” brought on by cold, windy weather.
Spots: If you’re noticing spots on your vine’s leaves and fruit, it’s most likely due to fungal diseases such as alternata spot or brown spot.