Why does my Passion Fruit Creeper grow best in autumn and early winter?

Question

I live in Cape Town South Africa, which is a Mediterranean climate (similar to Southern California, I think). I'm growing a Passion Fruit creeper. Now I assumed this would grow best during summer (with a bit of watering).

I've noticed, for the second year now, that the creeper grows best from about April to May which is actually our Autumn going into winter. How can this be? The sunlight is weaker and the temperature is colder; it doesn't make sense to me.

The only thing I can think of is that it enjoys the higher relative humidity at this time of year. In summer it's dry here and in winter it's cool and humid but never freezing.

Any ideas or is this just an anomaly?

Answer 1

The answer might be that the sunlight is weaker, as you put it. Although Passiflora likes sun, even in the UK the advice is to protect or shade from very hot sun from late spring to early summer, which implies this plant grows better when the sun is less strong. Certainly, sunlight in the UK during April, May and early June is stronger in terms of UV than it is in July and August, so this might be the explanation.

If, though, your Passiflora is planted somewhere which is shady during the hours of 11-3 in summer, this won't be an appropriate theory.