Now I don’t want to gloat, but here it is winter and we’ve been enjoying delicious, homegrown passionfruit for months. Which is just as well for my vine’s survival, as we didn’t see any crop at all last summer. Spring and most of summer went by with lots of growth but few flowers. It was if you recall a cool, grey summer along the east coast, but towards the end of summer the vine gave up sulking and burst into flower. By the first days of autumn it was bedecked with green fruit.
Often this late crop just sits on the vine and then is discarded before it ripens. But this year the crop held on – despite frosty mornings and cold, windy days – and has ripened.
The fruit hasn’t ripened all at once but gradually giving me a steady supply to eat fresh with a spoon or as a topping for yogurt or fruit salad. Now the chooks are back in production I should lash out and make a pav, which is surely the traditional place to use passionfruit.
Passionfruit is an interesting plant but not without its problems. It is one of Australia’s favourite backyard crops but I’d venture to say it brings more questions to talkback garden shows than even lemons do.
The main concerns revolve around fruit (or I should say lack of it) but gardeners are also concerned about when to prune it and how to feed it. More recently suckers are showing up as a problem too.
Pests – from passionvine hoppers to rats – also raise concerns. There have even been questions asked about passionfruit on this site.
After many years of both growing passionfruit and also advising others, I’ve decided that to grow a strong, productive passionfruit vine is part good gardening and part dumb luck.
The first thing to realise is that passionfruit grow on vigorous vines. This means they need space both above and below ground and also need support in the form of a trellis or a fence.
They also need full sun, good drainage and shelter from the cold. Fertilise vines with pelletised chicken manure or citrus food, spreading fertiliser along the root system. Water well particularly after planting, while times are dry and when plants are flowering and crops are maturing.
Passionfruit Nellie Kelly
Nellie Kelly, a large-fruited black passionfruit, is the most popular homegrown variety and the one I am growing, but others you’ll come across at the nursery are Panama Red, Panama Gold and Pandora. These last three do best in warm or at least coastal climates. I wouldn’t expect any of them to fruit here in Kurrajong.
Another bone of contention with passionfruit seems to be whether or not they need a ‘friend’. Some Panama varieties for instance fruit better with cross-pollination (that is two vines) but Panama Gold Select is self-fertile. Nellie Kelly is also self-fertile.
Popular in days gone by was the banana passionfruit (Passiflora mollissima), but it is now considered a weed. This species was popular as, not only easy to grow and it grew on its own roots, but was it is self-fertile and produced lots of elongated yellow banana-shaped fruit.
For decorative rather than fruiting passionfruit there is the beautiful scarlet passionflower, Passiflora coccinea, also known as red granadilla and for cold climates there are ornamental forms of the blue passionfruit, but I’ve not seen these growing in Australian gardens.
Decorative Passiflora coccinea (photo by Bouba)
Passionfruit though are basically are warm climate plants. Tropical, subtropical and warm coastal zones grow the best passionfruit although there is a passionfruit farm just up the road from us in Kurrajong Heights – or at least there was one. The passionfruit flourished in what is a frost-free microclimate with fertile soil.
Cold conditions and wet soils can lead to poor growth, death of the vine or poor fruiting so always plant passionfruit in a warm, sunny, sheltered spot with free-draining soils. Passionfruit need lots of space for their root systems so don’t grow them in pots.
In tropical and subtropical climates, passionfruit vines fruit within six months of planting. In these climates spring-planted vines may be fruiting by late summer and fruit production continues through winter.
In temperate zones vines however can take 18 months to reach maturity – so that’s a year and half before you can expect them to begin flowering and fruiting. That’s a long wait! Indeed, a spring-planted vine may not flower and fruit until its second summer so that’s quite a long time when plants may only survive for five years before they are hit by virus disease and die.
But a lack of fruit isn’t always just due to immaturity. Lack of regular water, lack of pollinators or even sudden cold winds can all take their toll on fruit. Too much shade can also slow ripening and this is where pruning can be effective. In late winter or early spring carefully remove some of the tangle of stems so that fruit and flowers when they appear are better exposed to the light.
‘Fluffybum’
Fruit that falls from the vine but isn’t black may be ripe (so always check) but it can also be dropped if the weather suddenly turns cold or the plant lacks water. Pest insects such as passionvine hopper feeding on the vine can also lead to fruit drop. Watch out for these insects while they are young. They appear as ‘fluffy bums’ – that’s the name given to the cute-looking nymphs. They are easier to deter with a jet of water or control with a chemical spray as juveniles than as adults (which resemble lacy-winged moths).
But getting back to passionfruit. Fruit colour at ripening can be variable. Usually green fruit ripens to purple or black but 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, despite it not being highly coloured. 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.
Fruit that forms but contains little pulp may have been poorly pollinated, but again there can be other things going on such as stress due to insect pests, cold or lack of regular water.
Lots of flowers but no fruit may be due to poor pollination. If the weather is cool, wet, windy or even overcast during flowering, pollination and fruit set may be poor. A lack of pollinating insects (often made worse by bad or cloudy weather) can also affect cropping. Hand pollination (using a dry paintbrush to transfer pollen to the female part of flowers) can overcome some pollinating problems and is most successful done early in the morning.
Encourage bees and other pollinating insects to vines by planting herbs such as borage.
My biggest beef with passionfruit however is suckering. Most passionfruit are grown as grafted plants to overcome problems with fusarium wilt and other soil-borne fungal diseases. Home garden plants are usually grafted on to blue passionfruit (Passiflora caerulea).
Blue passionfruit is a vigorous plant that may sucker particularly where there is root disturbance or if the grafted part (the scion) dies. It produces inedible yellow fruit, but this fruit also helps it to spread.
Distinctive 5 lobed leaves on suckering understock
Watch for suckers (look for the distinctive five fingered, blue-green leaf as well as its blue flower) and remove suckers or seedlings promptly. If a vine dies carefully dig up the root system to avoid future problems.
There are other rootstocks and I do wish they were used more for home garden varieties. Commercial vines are usually grafted on to Passiflora edulis f. flavicarpa, a rootstock developed in Queensland that is disease resistant and not prone to suckering.
Some varieties are also grown from seed or cutting to overcome suckering problems. Panama Red and Pandora may be sold as seed grown plants which means they are growing on their own roots.
Passionfruit make excellent screening plants and add a lush leafy tropical feel to the garden. But, if you plant one, remember that they’re not always going to be trouble free, but most come good and produce truly delicious fruit. Speaking of which, I’ve just collected eight eggs from the chooks and a dozen fruit from the passionfruit so I am about to whisk up that pavlova to celebrate.
[Like to know more? Here's another post on Growing Passionfruit by Marianne Cannon]
How I envy you the ability to grow fruiting passionfruit. I used to live in Normanhurst, on Sydney’s North Shore, and we had a big old house that had both regular passionfruit and banana passionfruit. I don’t quite understand why banana passionfruit should be considered a “weed” as we found their fruit to be absolutely delicious. I have grown a couple of passionfruit vines in New York City, but they don’t really thrive, and now, as a result of your article, I believe I understand why. They have always been potted, living outside during the summer and inside during the winter so they wouldn’t freeze. They have occasionally given flowers, and from the photos accompanying your article, is would guess that they are the variety Passiflora caerulea. I suppose that, because they need more room than a pot allows them, they just do not thrive. Thank you for the insight!
Hi Jennifer, what an informative and enjoyable reading this has made. So, I might not get fruit as soon as I thought, the bees seem lacking, but are plentiful in the rest of the garden so that is one clue as to why. Having the confidence to work with the brush and hand pollinate has always seemed to be so technical but we will have a go. Once again thank you for all the information.
Hi Jennifer, thankyou for the above informative article. We are finding lots of bees in the garden, mainly in the bottlebrush at this time, which is on the other side of the garden, but they have not found our passionfruit. So there is something to investigate, we are going to have a go at the brush to hand pollinate, but our confidence in doing this has been lacking, but if we do not try we will never know. But thankyou once again for the article. I am enjoying Garden Drum.
Lovely blog, Jennifer. I have had an interesting experience with my passionfruit vines this year, too. I planted two different varieties ( red and black) about two metres apart on the front north/west facing fence. I had been told they would cross pollinate thus.
I had rich and verdant growth of leaves and then flowers, turning into a stack of green skinned fruit which stayed just that – green. From May to June to July, the fruit stayed the same colour, although grew in size and number. They stayed mostly attached to the vine, with maybe a handful dropping off.
Eventually I started taking them off the vine and cut them open and voila, they were full of ripe, sweet pulp. So I harvested them, green and all, and slurped my way through dozens. The rest, I gutted and froze the pulp, and well, you know the rest; ice cream sundaes, pavlova etc etc.
Question is: why didn’t the skin “ripen”?, ie change colour ?
Thanks,
Julie.
Some varieties are not as black as others is the only thought I can offer! It is always worth doing what you did – cutting open the fruit and tasting it.
My passionfruit vine is now entering its 7th year! It started off as a $2 plant and was placed in side garden but did nothing over 18 months, so was duly moved to a spot alongside the carport. From there it has just flourished and I tend to prune it back quite brutally by at least a third every year. Whilst we had a ‘scant’ year last Summer due to the ongoing rains, this year it is again loaded with fruit. We were told that Passionfruit only last 4 yrs, but ours seems determined to keep on producing! I freeze lots of pulp for use throughout the year. Our biggest yield was 35 kgs two years ago.
Hi, Jennifer.
I have a Nelly Kelly Passionfruit, this is its second year, it is very vigorous but with very small fruit with nothing inside, just an empty shell, lots of buds falling off what is the problem ?
it gets lots of sun and water (I think)
hoping for an answer
Hoping for some fruit too I bet! I’ve found that deeply watering passionfruit at least once a week, making sure the water soaks in along the extensive root system really encourages all those flowers to make fruit that’s full of pulp. where you are finding dry passionfruit it is usually due to incomplete fertilisation (that is the female part of the flower just didn’t form seeds due to a lack of pollen). The passionvine hopper (pictured above in the blog) can also affect fruit formation so try to control that on your plant as well. There is still plenty of time for fruit to form and to ripen as passionfruit crop well into autumn and even through winter if the conditions are mild. Jennifer
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Can you please give some suggestions as to how I can get my passionfruit vine to throw flowers earlier. I have no problem getting them to set when they do turn up but March flowering means passionfruit in winter, which is no good. I was told to prune in september but that has not helped either.
I am in Perth.
Thanks in advance.
Pruning may have delayed flowering. Deep watering in spring and early summer should help encourage lots of flowers. I have noticed here in my Kurmond garden bursts of flowers after heavy rain or deep watering. Early blooms also may need to be hand pollinated if there is little bee activity when the flowers are open. Last year (2012) I had a mass of late summer and autumn flowers which matured into delicious passionfruit ripening right through winter (despite some cold nights and frost). When the passionfruit begins to re-grow at the end of winter also feed it with a flower and fruit fertiliser and feed again after rain in late spring or summer. Jennifer
Last year they started flowering in about march and I asked a gardening guru how to rectify the late flowering and she suggested pruning in september,but this has not helped.i also reticulate 3 days a week and have tried citrus fertilizer and also potash but no flowers as yet.
I can only say that passionfruit flower well if they are getting the right conditions, which are lots of water, full sun and regular feeding and a warm climate,. What you are doing sounds like good feeding and watering but if the soil is really porous and drains and dries fast, it may not be enough. As well as using the fertilisers for fruiting I would mulch with about 5cm of well-composted manure around the base of the plant and also try using a soil wetting agent to make sure you are saturating the soil. When conditions are dry – which they are in Perth and were in Sydney in spring – passionfruit do not flower well. You may need to increase watering. Remember too that passionfruit have an extensive root system so you may not be watering and feeding the entire plant adequately. Near by plants may also be competing for the food and moisture. Also look for and remove any suckers. Pests can also cause problems including passionvine hopper (small triangular green adults, fluffy bum young). And, if the vine is suckering that too reduces flowering as it puts the plant under stress.
My passionfruit is now about one year old, growing well but no flowers. I am thinking it may be a dodgey plant. Should I pull it out and start again. I live in Perth.
Passionfruit are not necessarily mature until they are over 12 months old so it could be worth persevering until next spring. However, do check that your plant is still the fruiting form and not the understock (see story above). With Perth’s sandy soil, passionfruit do need regular water and fertiliser to get established. Citrus food is a good all round food for passionfruit.
Jennifer
jennifer thank you for your info – but I have a self sown single vine. first year has produced a massive 100 plus crop in full sun, (sadly neglected) and have had a look today to see it in bud again. how many crops can I expect each year. The only luxury this plant has had is a handful of dynamic lifter..and good watering… when should I give a trim? I thank you most sincerely, joy
It depends where you live. In subtropical and coastal areas with a temperate climate passionfruit can fruit almost year round. Inland where I am we tend to get two distinct crops – one in late spring or early summer after the first flush of flowers an another in autumn which may continue to ripen into winter. Passionfruit have flushes of flowers and if these are pollinated they’ll tend to fruit so you can have fruit over many months. Here at Kurmond in the low Blue Mountains where we’ve had masses of rain the passionfruit are flowering and fruiting but I’ve had to hand pollinate them as the bees have disappeared from the garden since the massive heat wave. Good luck with your vine. Jennifer
HI all, Had a Panama Red here in Townsville. It produced about 250 fruit in its second year and same in its third then it died. I dont know why? I would like to grow another in the same spot and i would mulch more, which might give me more years. My problem is the possum got 460 of the 500 fruit. Any ideas?
Magnus
Not sure why the vine died and possum proofing is so tricky as it is hard to net or block access which are the only sure methods. You may have to consider pruning and training the vine so it can be netted in the future. In the meantime you could try putting exclusion bags over some of the fruit to see if that saves some of them. I know it sounds arduous but give it a try.
The things that can kill vines include virus and damage to the main stem. However three years is quite young for the vine to succumb to virus disease.
Jennifer
I have a fairly new Passionfruit vine, approx 2 yrs old that has suddenly filled with flowers which have now become huge fruit, probably as big as a tennis ball and heaps of them. I am wondering what type it is, as I planted a few along that fence in the hope that one would do the right thing and produce. I have mislaid the labels, but know I definitely bought a Panama Red as well as a Nellie Kelly. However the fruit on this vine is totally different in shape and size to my old regular run of the mill Passionfruit that turns deep purple in Summer. The fruit seem to have been green for quite a while and I am wondering if due to it being Autumn, they will take a lot longer to ripen? It receives plenty of sun, is on a fence and we also fertilised with Alpaca manure.
My Nellie Kelly passionfruit vine is also covered with round green fruit at the moment (late April). If your fruit is very large however it may be that it is the Panama that is cropping. Either way the fruit may or may not ripen over the months ahead. If the weather stays mild and the passionfruit is in a warm, sheltered location you may find yourself in the delightful position of being able to harvest ripe passionfruit right through winter. But, if conditions turn cold, the fruit may fall to the ground unripe. It is however always worth cutting open fallen fruit to check for ripeness. I have my fingers crossed for a warm autumn to ripen the fruit on my vine (and yours). Jennifer
Hi Jennifer, great lot of info. I have a few queries.
I have a “Golden Nugget” vine which has massive yellow fruit, about orange size, beautiful. The vine, (in it’s 2nd. year) has grown on the fence
about 7m each way. Should i prune it back, if so how, & how much.
Also i’m not sure about these suckers, what they are, where they grow.