Grafted vs. non-grafted passionfruit vines
Nellie Kelly is most famous for its unique method of grafting popular passionfruit vines onto a hardier rootstock vine. This creates plants that are less susceptible to disease, pests and frosts and allows for greater fruit production.
The official rootstock of all grafted Nellie Kelly Passionfruit vines is the blue passionfruit (Passiflora caerulea) which replaced the original rootstock of banana passionfruit (Passiflora mollissima) over sixty years ago.
While Nellie Kelly’s grafted passionfruit vines have obvious advantages there are certain circumstances where the non-grafted varieties are more suitable. Nellie Kelly’s non-grafted Black and non-grafted Banana Passionfruit vines are recommended for gardens with coarse or sandy soils where grafted vines would be prone to suckering. These non-grafted vines also thrive in warmer, tropical areas where frost is not a problem.
Planting your vine
Nellie Kelly Passionfruit vines should be planted in sunny, well drained areas where they are protected from the wind and their rapid growth can be supported by a strong trellis, fence or building. Expect them to grow to 6 metres square over the summer months, with the added weight of 300 to 400 pieces of fruit a season.
The vine is best planted facing north or where it can get the 4 to 6 hours of direct summer sunlight it needs to ripen the fruit. Planting in a shadier position will result in lots of green foliage but unripe fruit. The best time to plant your Nellie Kelly Passionfruit vine is in early spring after the cold weather has passed.
Fertilising your passionfruit vine
In the days before synthetic fertilisers, it was common practice to place a lambs heart or ox liver in the ground with a passionfruit vine to provide the iron and nitrogen it needed. These days you can use an organic blood and bone fertiliser raked into the garden bed or a top-dressing of aged chicken manure.
Fertilise your passionfruit vine early in the spring after a thorough pruning and then again after the fruit has been picked. Over fertilising will cause the flowers to drop off and prevent fruit from forming.
For new plants, fill the bottom of the hole with some blood and bone first, and for developed plants spread the fertiliser over a wide area around the base of the vine before gently raking in and giving a light water.
Pruning your passionfruit vine
For optimum fruit production and plant health, it is important to prune passionfruit vines each spring to promote new growth where the flowers and fruit can form. The best time is in early spring, after the last of the cold weather. Remove a third of the previous year’s growth and leave the major runners and laterals on your trellis. Neglecting to prune your vine can result in unwanted disease and poor fruit production.
Fertilise after pruning by spreading a good top-dressing of blood and bone or aged chicken manure in a wide area from the base of the stem. Rake this in lightly and water.
Passionflowers & passionfruit
Due to the bisexual nature of passionflowers, one plant is capable of fruiting heavily on its own. Unlike the kiwi fruit, there is no need for a male and female plant.
Flowers generally appear in mid-spring before setting to fruit in early summer. Application of superphosphate around the base of your vine will encourage flower growth, while adding potash will help them set. The fruit that forms needs several solid days of direct summer sunlight to ripen, resulting in a darker, wrinkly skin.
Always water widely around the base of your passionfruit vine while fruit is ripening, especially on hotter days. Lack of sufficient water during this period results in fruit with poor quality pulp and little juice.