sick passionfruit vines

[kcuddon]

I have two passionfruit vines. Both are sick. One has completely lost all its leaves and I’m worried the other is going the same way. They are planted next to each other facing north. They are about 18months to 2 yrs old. I water them regularly. What am I doing wrong?

[JacobZ]

Hi @kcuddon,

Welcome to the Bunnings Workshop community, it is fantastic to have you with us.

With passionfruit, sudden leaf drop and decline are usually caused by a combination of factors rather than one single issue.

One of the most common problems is overwatering or poor drainage. Passionfruit like consistent moisture, but they hate sitting in wet soil. If the ground stays damp for long periods, the roots can rot, which often shows up as yellowing leaves followed by leaf drop and vine collapse. North-facing positions are good, but if the soil is heavy or the area does not drain well, regular watering can actually make things worse. What is the soil like? How does it handle watering? Does it drain well? Some information about the soil could certainly help us.

Another possibility is nutrient imbalance. Passionfruit are heavy feeders and need regular fertilising, particularly potassium and trace elements. Deficiencies can cause pale leaves, weak growth and eventual leaf loss. On the flip side, too much nitrogen can encourage lots of soft growth that is more vulnerable to disease. Have you applied any kind of fertiliser? And if so, what did you use?

Disease is also worth considering, and I suspect this is playing a major part, especially since both vines are affected and planted close together. Fungal diseases such as Fusarium or Phytophthora can cause rapid decline, wilting and leaf drop. Viral diseases can also lead to distorted leaves, mottling and gradual dieback. Unfortunately, once a vine is badly affected by these diseases, recovery is unlikely. You could try using Yates Leaf Curl Spray, but I suspect things are probably too far gone for this to be an effective approach.

Any further information you can provide will help us moving forward, although I don't think the outlook is good.

Allow me to tag our experienced horticulturalists @Noelle, @mich1972 and @robchin to see if they have any thoughts.

Jacob

[Noelle]

Hi @kcuddon 

Your passionfruit vines are certainly unhealthy and, in my opinion, are probably not likely to thrive as there is no new leafy growth on the stems trained up the fence. The way the vines have been trained is quite severe - generally they do best when allowed to 'do their own thing' over a lower fence or trellis, where they will intertwine and become quite dense. Any new growth is along the top of the fence.where it is exposed to wind and harsh sunlight.

Fertilising and watering are very important particularly in the first year or so after planting - both vines look as though they have not had sufficient of either. I'd be inclined to start again, and allow the vines to develop more naturally along the fence rather than training them vertically.