(Nederlandse versie hier)
Passiflora is a genus of several hundred species of plants, known for its unique and sometimes quite spectacular flowers, and therefore popular with lovers of exotic plants. Different species are used in different ways: The common passion fruit (P. edulis) is eaten as a fruit, while P. Incarnata is used in herbal medicine as a sedative. But most species are just grown for their beautiful flowers.
Passiflora caerulea – blue passionflower
Here in this corner of Europe that’s not without problems: Passion flowers are very beautiful and generally fast-growing climbing plants, but they often need tropical or subtropical climates to thrive. So here in Flanders we’re just at or just below the Northern Border for the most cold-resistant passion flowers that grow well outdoors. There are some species that grow reasonably outside here, until a very severe winter shows up that is. The common blue passionflower (P. caerulea) is the best-known species here and also the best-adapted to our climate. The maypop, Passiflora incarnata can survive even colder winter temperatures, but it completely freezes off in cold climates every winter and then needs to grow back completely from the roots, needing summers more hot than ours to have much flowers and fruits.
(I leave out the northernmost species P. Lutea here, the yellow passionflower which has no ornamental value and is reportedly not the easiest plant to grow.)
Tucumanese passionflower – Passiflora tucumanensis
There are a number of hybrids and ornamental varieties that are grown, some of which very nice. But there is also another less known wild species that should be almost like P. Caerulea when it comes to coldhardiness, the P. Tucumanensis (sometimes called P. Naviculata). This is a South American species that grows in mountain areas and so is accustomed to cooler temperatures.
The Tucumanese passionflower, as its name can be translated, is named after the Argentine province of Tucuman. It has small soft-green ternate lobed leaves and hanging passion flowers, slightly smaller than those of the blue passionflower. The flowers, that are only open for one day, have a spectacular purple-white corona.
Earlier his summer I had ordered a plant of this and some other species from de passifloratuin, and today the Tucumanese Passionflower is the first of those plants that blooms. It is stil to be seen how well it does in the long run, but of all my Passiflora plants I have here now it is the one that continued to grow most in August which was exceptional cold and wet… So maybe it’s indeed a plant that can withstand cooler summers. We will still have to wait and see what happens in and after the winter though…
Tucumanese Passionlfower – Passiflora tucumanensis
But there is more: If we look edible fruit this one might actually also be interesting. The fruits are described as small, but with a very delicate aromatic flavor which is even better than the common passion fruit. What makes it more interesting here than P. Incarnata which generally needs a longer and much hotter growing season to form ripe fruit than we have, and P. Caerulea which sets fruit here, but is not known for its good taste … (and all hybrids, which have reduced fertility, which is not very convenient if you like to have a lot of fruit)
The problem here is that Passiflora-species are generally self-incompatible, so you need at least two genetically different plants (that means no clones which come from cuttings taken from the same mother plant) and I have only one at the moment …
But we’re working on that, so probably this story will be continued one day… The first impressions of the Tucumanese passionflower are very positive right now though…