How to grow passionfruit
Grafted passionfruit are said to fruit earlier and better, but for my money I’d rather grow them from seed. My first passionfruit plant was a grafted ‘Nelly Kelly’ that I bought from my local nursery. Much to my dismay, this plant never yielded me one passionfruit! What it gave me was hours of weeding out the suckers from one end of the garden to the next. It was then that I vowed never to get another grafted plant again but grow it from seed instead.
Passionfruit only last about 7 years so it’s important to get some stock growing well before your last one dies. Before I finally gave up on the ‘Nelly Kelly’ I got started on a some seeds that I got from Diggers Club for a common black passionfruit, Passiflora edulis. There weren’t many seeds and they took a long time to germinate, maybe up to one month. So be patient if you try at home!
Being a vigorous climbing plant, a passionfruit can take over pretty quickly and can be a pain to keep tidy if left unpruned. If it’s not pruned then it becomes less productive and woody. So it’s important to train the vine onto a very secure support to get the most out of your plant.
I germinated the seed in spring and then planted the seedling into a 100mm pot to get a bit bigger. It was quite slow to start with, perhaps I didn’t give it enough compost in the potting mix to boost it along. But for the first year I only got one long shoot. This becomes the main trunk of the plant and the base for which all the next year’s growth comes from.
By the second spring, I planted my shoot out into the garden and enriched the soil with compost and mulch. This gets everything growing now and forms the framework for the entire plant. Pinch out the tip of the shoot and attach the side shoots horizontally to the vertical plane to encourage the main branches to grow. These branches will alternate along the main trunk of the plant (the bit that grew for the first season). You won’t get any flowers yet, so again be patient! It’s important to shape your vine like this because it’s going to make pruning a whole lot easier in the long run and your plant’s going to produce some mighty fine fruit if you do.
By the third spring, i.e. 2 years after sowing the seed (yikes, it takes that long!) you will get lateral shoots from the branches. These are the fruiting limbs (finally!). Flowers develop all the way down these limbs at the leaf axil. Let these limbs just fall in front of the main branches rather than letting them get tangled in with the rest of the plant. This can become somewhat difficult with very opportunistic tendrils finding anything to cling onto as soon as they touch it. You should bear fruit from this lateral growth every year now.
After harvesting fruit in autumn or winter, leave the plant to loose it’s leaves if you’re in a cool area because they act like a semi-deciduous plant. If you’re in warm temperate climates the leaves will stay green all year round.
In early spring it’s time to prune before the new growth takes over. You want to now trim back all your lateral growth from last season to about 3 leaf nodes. By doing this you shorten the laterals back close to the main branches. You’ll see the framework of the vine now. The laterals will start to put on growth with a vengeance, so now you simply do what you did last season and let the laterals hang down towards you and watch them flower. Flowers will only be produced on the new growth so if you don’t prune back last year’s branches, you’ll start getting growth starting from the tips of last year’s laterals. Each lateral is capable of growing 1 to 1 1/2 metres (yards) per season. Without pruning you’ll end up with 3 or 4 metre (yard) long branches with flowers only on the last 1/2 metre (yard) and the rest of the vine will get all woody and hard to hold up.
Good pruning means that very spring you keep taking the laterals back to the main branches to within about 20cm (8 inches) of the branch. This way it stays vertical rather than sprawling all over the place and encourages more flowers and fruit.
Remember passionfruit needs enriched soil with loads of compost and mulch every year, but don’t give too much manure otherwise you’ll end up with lovely green leaves but no flowers. Also choose a self-pollinating variety if you only have space to grow one vine. One vine can grow 2 meters (yards) high and have main branches reaching 6 metres (yards) along a fence or support structure.
Vine trained and pruned – check.
Flowers pollinated – check (make sure there’s plenty of bees around).
Fruit is on it’s way to maturity – check.
All that’s left to do now is to find that old recipe for passionfruit yo-yo biscuits … YUM! YUM!