Horizontal trellises have cross-pieces at the top of each post with 2-4 wires strung horizontally 60 cm (2 ft.) apart along the top of each cross-piece. Vertical trellises consist of heavy posts without cross-pieces, with 2 or 3 wires strung along the row like barbed wire fencing, attached to the posts from the top down at intervals about 30-40 cm (12-16 in.) apart. 1
Trellis wires should be No. 9 or 10 galvanized steel. The posts need to be stout enough to withstand the weight of the vines throughout a season that normally includes the buffeting of strong winds. Ideally they should be long enough to provide a trellis height of 1.5 m (5 ft.), with 45-75 cm (18-30 in.) in the ground. Trellis rows should be oriented north-south for maximum exposure to sunlight, and the vines should be allowed to grow together along the trellises to promote cross-pollination. 1
Passion vines in their native state clamber up available trees or rocks and spread out to catch the available sunlight. The yellow passion fruit has naturalized in this manner in some parts of southern Florida. In cultivation, vines should be trained to cover the wires of the trellis or fence on which they are grown. 1
Young vines are trained by aiming a growing up toward the top of the trellis and once there, allowing a shoot to grow along each wire in each direction. A 2-wire trellis provides 4 sprouts growing along the trellis away from the vine's trunk. Once started, the vine should be allowed to grow without pruning throughout the season, since the more vine there is, the more bearing surface there will be. With self-incompatible forms of yellow passion fruit it is particularly desirable to allow 2 different, cross-fertile vines to grow through each other and intertwine so as to promote heavy fruit production. 1
Depending upon the trellis design, vines should be trained to grow in a manner that maximizes the canopy surface area. An option is a “curtain” training system (Fig. 1), in which one main stem reaches to the top support wire, with vines spreading horizontally and then drooping down like a curtain to fill in the open space below. 2
If laterals do not emerge in time, they can be forced to leaf out by pinching off the shoot tip. When the vines reach the wire they are trained in opposite directions along it. All laterals below the wire are pruned off. Laterals emerging along the wire are allowed to hang down freely; they are the secondary shoots branching into tertiary shoots. Secondary and higher order shoots are the fruiting wood which has to be thinned and rejuvenated by pruning. 3
Vines should be pruned in late winter when they are not actively growing. Use a 10% bleach solution or quaternary ammonium to disinfect cutting tools between each plant to avoid spreading disease. Over time, if left unmanaged, the new vine growth may become dense and cover older vine growth that loses its leaves, forming a thatch-like canopy composed of dead leaves. This can be a source of fungal diseases that negatively affect new leaves and fruit quality. 2
Vines can be pruned back to the main vine or healthy branches from the main vine. All dead and weak stems should be pruned out and pruned back to vigorous stems so that they can resume healthy, active growth in early spring. A good time to make the first fertilizer application is after pruning. 2
The passion vine is a short-lived perennial. Some yellow passion fruit vines in southern Florida have persisted in the field for 10 years, but this is exceptional. A more realistic life expectation is 3-5 years. A vine that appears to have excessive deadwood may have lost so much vigor that it should be removed and replaced with a young, healthy plant. 1
You can expect fruit about 18 months after planting. If your vine is not fruiting after this time, it may be due to one of the following reasons.
It needs more water. Passionfruit vines are heavy feeders and need plenty of water. A dry plant will not produce fruit, so ensure the soil is moist.
Heavy rain during the flowering phase can ruin the viability of the pollen and cause a lack of bees for pollination. You can self pollinate using a small paintbrush or toothbrush to transfer pollen from one flower to another.
Overfertilising results in flowers but no fruit. Passionfruit usually only needs fertilising twice a year, after pruning and again after fruiting.
Yates Thrive Citrus Plant Food is a fertiliser high in nitrogen, this promotes plenty of passionfruit leaf growth at the expense of fruit and flowers.
5 hours of sunshine. Passionfruit require at least five hours of direct sunshine a day. They should be planted in a sunny spot with no trees or competitive roots.
Passionfruit fruit is empty?
This can be caused by overfeeding or an result of weak seedlings. Follow the fertilising guide on pack and if the issue continues it may mean that you need to start again from scratch.
Passionfruit is falling off before it’s mature?
This can be caused by extreme cold weather or the plant not getting enough water.
If the soil around your plant is dry the fruit may shrivel and fall prematurely. Be sure to water frequently in short intervals in dry times to keep it growing and healthy.
Passionfruit would have to be one of my favourite fruit. The passionfruit vine is a strong, vigorous, evergreen climber, and it originated in South America.
A great spot for a passionfruit vine is one that's out in the open, has full sun and no trees or competitive roots. Grow it on a structure like a strong trellis.
Passionfruit vines are known for their tendrils, which are little curly spring-like things that attach themselves to wire and really grip on like a python. That's how they climb.
Often what happens with a passionfruit vine is there is green growth on the outside, where the tendrils have attached themselves, and they have woody material in the centre.
In late winter and early spring it's time for a clean up. You don't have to prune hard every year. But in early spring take off about 30 centimetres - that's ideal.
One of the vines that Gardening Australia filmed suffered signs of stress. It had scale - insects that were sucking the sap and the life out of the plant. There was evidence the bark of the main stem was splitting, because it had been tied up, and there was some form of collar-rot at the base. The poor old vine had to go to passionfruit heaven.
There are many different varieties of passionfruit. Some to look out for include:
The grafted Panama Gold - which has big fruit and its skin is a golden yellow colour.
The Panama Red - which is red skinned, has rather large fruit, and is also grafted. Both are good to grow in the tropics.
But for southern Australia, the grafted Nelly Kelly black passionfruit is my choice.
In the olden days every passionfruit vine was planted on top of a lamb or sheep's liver, ox heart, or some other piece of offal, to provide iron. Stick it at the bottom of the hole, cover it up a little bit, and then plant the passionfruit as normal.
If you don't want to use a lamb's liver, or offal, you could use pelletised chook manure. And scatter that about a metre around the root system. Do this about twice a year. Remember that passionfruit vines are also hungry and thirsty and love a well-drained soil. It's also a good idea to put some mulch around the root system, to protect it from the hot sun.
In its first year the little vine will tendril its way across the wires. Just nip out the top little bud and it will shoot out laterally. This means you'll get lots of side shoots, and expect fruit in about 18 months.
Given plenty of food, well-drained soil and lots of water, you will end up with a great passionfruit vine. And, a little tip - when you see the fruit developing, get your little child to get a nail and scratch their name into the fruit and you end up with your own branded passionfruit.
Storms can certainly play havoc when they hit, especially in the garden. If your passionfruit has dropped its fruit due to a storm and the fruit is still green, then, unfortunately, they are unlikely to sweeten up.
You would normally pick the fruit when it has changed from green to purple thus allowing as much time as possible for the fruit to mature and ripen on the vine.
All is not lost, your vine will produce again next year, so come spring, fertilise the vine with some Yates Thrive Citrus & Fruit Granular Plant Food to encourage flowering and fruiting. Give ample moisture to the vine during the hot summer months and next summer/autumn your vine will reward you with lots of delicious sweet fruits.
Take the worry out of growing this popular backyard crop with these tips. Remember passionfruit are subtropical plants so, although they’ll grow in most parts of Australia, in cooler areas they need a warm, sunny, sheltered spot with fertile soil and regular water to thrive. Plant a passionfruit vine between spring to early autumn and provide it with a wall or framework to climb on.
1. Age before beauty
Passionfruit vines don’t flower and fruit straightaway. In the subtropics they may begin fruiting in six to 12 months from planting, but in most parts of temperate Australia it takes 18 months before flowering begins and fruit forms.
2. Feed and water that growth
Keep these hungry vines weed free, well watered (especially when there’s little rain) and fed from spring to autumn. Use pelletised flower and fruit, a citrus food or a chicken poo fertiliser. Water plants well before adding fertiliser then spread it around the base of the stem and along the area where the roots are growing. After feeding in spring, spread organic mulch such as compost or aged cow manure 2 to 3 centimetres deep. Don’t let it build up against the stem and don’t dig it in as this may encourage suckering.
3. Avoid suckers
Many passionfruit are grafted plants. From time to time the understock (the root system your vine is grafted on to) starts to grow. It can out grow the productive vine and become weedy. Always remove suckers from below the graft area and avoid damaging the root system as this can encourage suckering.
4. Pruning
Passionfruit vines don’t need pruning to encourage fruiting, but they may need it to remove overgrown growth or keep the vine under control. The best time to prune is in spring as new growth resumes. Avoid removing main stems, just cut back unwanted twining stems.
5. Flowers but no fruit
If the vine is established and well cared for it should begin flowering in spring and continue into autumn. All being well these flowers are quickly followed by green fruit, which gradually ripens to black or purple in the case of ‘Nellie Kelly’ or golden brown or red in the case of other varieties such as ‘Panama Gold’. If there are flowers but no fruit, try hand pollinating the blooms using a small dry paintbrush or a cotton bud to transfer pollen from stamens to the stigma. Repeat this regularly until you see fruit forming. You can also try planting flowering annuals or herbs around the area to entice pollinators into your garden.
Rain, overcast conditions, cold and wind can all delay fruit formation. Over fertilising with a high nitrogen fertiliser can cause flowers to drop and prevent fruit from forming.
6. No flowers
If you've planted the vine in the correct position and you're still not getting flowers once established it's likely not getting the nutrients it needs. Try feeding in September after pruning and again in autumn with a liquid plant food such as Amgrow Organix Harvest or Yates Thrive Flower and Fruit.
7. Cross-pollination
Some passionfruit varieties require another vine to provide cross-pollination and produce fruit however the commonly grown ‘Nellie Kelly’ and ‘Panama Gold Select’ are self-fertile.
8. Pests
Passionfruit vine hopper, also known as fluffy bum due to the appearance of its young, can attack vines and may lead to fruit or flower drop. These can be squashed or hosed off. Juvenile fluffy bums can be treated with a garden spray such as a pyrethrum-based insecticide (apply according to label instructions). Vines may also be attacked by scale. Use a horticultural spray oil to deal with scale.
9. Is it ripe?
Fruit colour at ripening can be variable and some ripe fruit may not be highly coloured. If green fruit drops to the ground it is always worth tasting it to see if it is ripe. Fruit that’s fallen but has no pulp has not being properly fertilised. Ripe fruit left on the ground may get sun burnt so regularly collect fruit. Also keep the ground around your passionfruit clear of weeds or long grass so it’s easier to find fallen fruit.
Check out our passionfruit factsheet here.