The Passionfruit vine is one of the most popular garden plants in Australia. It’s easy to see why, when they produce beautiful purple and white flowers, followed by loads of delicious fruit, all against a lush green backdrop. And the best part is that it can all be achieved in a small vertical space.
At the nursery, we get quite a lot of questions about passionfruit and the problems that can occur when growing them. Now is the perfect time to plant, as the weather’s finally starting to warm up. And so I thought I’d use this opportunity to tackle these common problems head on, and turn all your frustration into fruit!
If you’re starting afresh or planting your first passionfruit this season, some of the fundamental elements to be concerned with are- variety, position and soil preparation. These are all key factors and will almost certainly be the difference between handfuls of fruit or bucket-loads.
VARIETIES: If you’ve ever been shopping for a passionfruit, you’ll know there are many varieties available. Lean toward the non-grafted types, as you’ll find that, almost without exception in times of stress and in our hot summers, grafted varieties tend to sucker like crazy and become an absolute nightmare for you (and quite possibly your neighbour). You will be forever battling to rid the yard of the rambling rootstock as, unlike the top half of the passionfruit, it can be quite resilient and weedy.
My personal favourite is the Norfolk Island Black passionfruit. It’s a good, sweet, and prolific producer, and relatively hardy, tolerating most hot “Wingham weather” once established. However, Panama Red, Panama gold, and Banana passionfruit are also worth considering, and tend to perform really well in our area too.
Here at the nursery, Ralph has always told me “don’t bother with anything other than the good old-fashioned Norfolk Black”. For as long as I can remember, he’s maintained that they are one of the most heavy cropping and sweet tasting. And, after all the different varieties that I’ve tested to date, he may well be right. I don’t dare tell him, ‘though!
POSITION: once you’ve got your chosen vine for the job, it’s important to find a suitable position. Full sun is imperative as is also a good sturdy trellis to support all those buckets of fruit. In the case of passionfruit, a North-South aligned trellis is ideal. This ensures that even growth is maintained on both the East and Western sides, as the sun’s orbit progresses throughout the day.
SOIL PREPARATION: When preparing the soil, it’s important to remember that, as with all productive plants, passionfruit are very hungry and thirsty and flourish in relatively free-draining soil. So, if you’re dealing with clay, as I expect will be the case in many parts of the Manning Valley, planting on mounds made up of free draining media may be a better option.
Although, regardless of mounding or planting in good existing soil, it’s a good idea to further enrich this soil by digging in pelletised fertilizer suitable for productive plants, together with compost, blood and bone or rotted animal manures. This will not only keep the microbes happy in the soil, but it’ll also add essential nutrients for that hungry passionfruit to use at its disposal.
Applying mulch is useful too, as it will serve by retaining moisture and keeping the roots cool when progressing into summer. Just be mindful of keeping it a good distance from the trunk so as not to encourage collar rot.
If you have some Seasol or other liquid fertilizer, it’s also a good idea to it give a good water in at recommended rates.
Lastly, be patient; the most important thing to remember here is “age before beauty”. Passionfruit vines don’t flower and fruit straightaway. You’ll be rewarded for your efforts in six to 12 months from planting.
However if you’ve already got a vine, and you want those bucket-loads of fruit, there are a few things that can be started to get things off and producing. Feeding and watering regularly are two of them. Fertilising now and then after the summer harvest is a good idea. If conditions are dry, water deeply once a week during the warmer months and mulch well. Passionfruit roots spread far and wide, so concentrate feed, water and mulch to a 2m2 radius from the base.
Regular observation and removal of dead and diseased material is also advantageous.
Most passionfruit vines remain productive for five or so years, so plant a follow-up vine in the third year to guarantee a continual harvest.
The most common questions asked at Wingham Nursery:
1. Why does my vine produce flowers but no fruit?
This is due to poor pollination generally by lack of bees. Rain, cold and/or wind can also reduce the viability of the pollen. To overcome this, try hand pollinating the blooms using a small dry paintbrush. Transfer pollen from stamens to the stigma early in the day. Repeat this regularly until you see fruit forming. You can also try planting flowering annuals or herbs around the area to encourage local bee populations. Plants like basil, marigolds or sweet alyssum are great choices.
2. What are the unusual shoots appearing at the base of my grafted vine?
These are suckers growing from the rootstock and need to be removed, otherwise they will deprive the vine of the energy it needs to thrive. Cut the offending shoots near the base with secateurs as soon as they appear.
3. Why does fruit form but drop off before maturity?
Dry conditions are often the cause. To avoid this, give roots a regular deep soaking in prolonged dry periods, and mulch well.
Caitlin Sawyer
Wingham Nursery & Florist