Heights of Passion
Ask me to recommend a useful climber for covering ugly boundary fences in a flash and, nine times out often, I?ll nominate passionfruit. Quick-growing with lush foliage and exotic, intricate flowers, this Brazilian subtropical vine starts bearing its purple fruit just 18 months after planting.
Passiflora edulis is versatile, attractive and remarkably easy to grow in frost-free gardens. It?s prolific too - outside the farmhouse where I grew up, a single vine kept our family and neighbours in fruit for well over a decade. It was never fertilised, watered, sprayed or indeed nurtured in any way, although my father would butcher it with a pair of electric hedge cutters from time to time.
Perhaps it?s nostalgia, but I can?t help but surmise that if one plant could produce so much fruit with so little attention, then growing passionfruit for profit must be a cinch!
When I suggest this to Tony Dimmock, who grows passionfruit commercially at Athenree, near Katikati, he laughs. It seems I am not the first gardener to view a copious home crop and start seeing dollar signs.
Passionfruit has been cropped here since the 1920s, when the first blocks were planted in Northland. New Zealand currently has 100 passionfruit farmers, based mostly in the Bay of Plenty, with a combined harvest of around 240 tonnes of fruit.
Tony Dimmock describes passionfruit as "a very rewarding, but often equally frustrating" crop. The reason is not so much scientific as social. Quite simply, passionfruit vines prefer their own company. Plant one in a home garden and it will flourish. Shove it in a paddock with a hundred mates and it is suddenly vulnerable to pests, diseases and declining productivity. "They are antisocial plants, and they make people antisocial too, because the harvest is so demanding. From the beginning of February until well into May, it is full on all day, every day.
"So if you think you can grow passionfruit as a weekend job, you are wasting your time. Training and picking the fruit is labour intensive and, after five years, the vines need replanting, which is why the industry is constantly changing over. For every new grower, there?s another who has got sick of it and decided to move on.
Which should not imply that there?s no money to be made. In a top season, premium export-grade fruit can fetch up to $40 for a two kilogram tray, and growers who get the jump on their competitors with early or late-season crops can reap up to a dollar for each fruit.
Having pointed out some of the pitfalls, let?s examine more of the pros. You don?t need a lot of land - the average passionfruit block covers only 0.4 hectares - about an acre.
The fence or pergola systems used to support the growing vines are not expensive and the plants are also relatively cheap. You can grow your own from seed for nothing, or pay around 50 cents per plant for tube-grown seedlings from a commercial propagator (these will need to be grown on before they are planted out). And you don?t need to invest in any fancy processing or packaging equipment - the kitchen bench will suffice for the first few years.
New growers are advised to start small, with no more than 200 plants. Four hundred plants is the maximum number recommended for an owner-operator any more and you?ll need seasonal staff to help pick and process the harvest. Choosing the right site is critical, as passionfruit vines require shelter and frost protection to thrive. Although the plants can survive light frosts (-1-2 degrees C), they do best in frost-free situations. Heavy or prolonged frosts will kill them outright. If frosts are uncommon, but not unheard of, in your region, it pays to protect young plants with bracken fern, newspaper or frost cloth.
Shelter belts should be well established prior to planting. "The better the shelter, the longer the plant?s life expectancy. The woodiness virus, which makes the fruit dry and thick-skinned, spreads quickly in plants stressed by cold, windy conditions," says Tony. Wind damage also scars the skins.
Passionfruit vines prefer free-draining, friable soils - the plants will not tolerate heavy clay - with an optimum pH of 6.0, but definitely no higher than 6.5or lower than 5.5.
Add a generous spadeful of blood and bone to each planting hole and feed new plants every four to six weeks with a nitrogenous fertiliser. Irrigation is beneficial in the first year, but regular watering isn?t necessary once the plants are established, unless you have light soil or experience extremely dry summers. Vines are best planted between October and January, spaced about five metres apart in rows with a north-south orientation. Kill off any invasive weeds like kikuyu before planting and keep the grass strips between rows regularly mown - if it gets too long you won?t be able to find the fallen fruit.
There are three schools of thought when it comes to training the vines. High-tensile, 1.8 metre high wire fences, with posts every five metres and strainers at the end of each row, used to be the norm. However, pergolas, such as those used to grow kiwifruit, and A-frames are now more common.
"We grow ours on two metre high A-frames, wide enough to get the tractor underneath for mowing," Tony explains. "It eliminates the sunburn factor. Fence-grown fruit has to be picked up several times a day to avoid sunburn blisters, but with an A-frame, fallen fruit is shaded by the canopy."
Growers should aim to export between 50-75 percent of their crop, with the rest sold locally or processed for pulp. "The price goes right down during peak production, but even when the local market is only paying $3-4 dollars a kilogram, you should still be making money. And you can make huge money if you have a site that allows for an early start in spring, or a really late winter crop.
Because it is so quick to mature, passionfruit makes an ideal short-term cash crop for lifestyle block holders, especially those waiting for other horticultural endeavours to reach fruition (the vines were often grown in new kiwifruit orchardists in the 1980s).
"If you?re looking for a rewarding crop for a small block," Tony Dimmock concludes, "passionfruit has to be near the top of the list.
As far as legal crops go, that is."
Article by Lynda Hallinan
Reprinted from "Growing Today" October 2001
