Passionflowers you’ll fall madly in love with

With an estimated 400,000 plant species on Earth, one of the best things about working in horticulture is that there are always, always new things to learn. Even when you have a genus so close to your heart that you think you know it inside out. Thanks to the ingenuity and dedication of breeders quietly working away in the background, sometimes you suddenly discover there are loads of new options that seem to have burst into bloom while your back was turned. One of the most wonderful examples of this is in the world of hardy passionflowers.

During my fieldwork for my masters in the high Ecuadorian Andes, I fell hopelessly in love with passionflowers. From the enormous pink pendant blooms of Passiflora mollissima that scrambled up forest trees to attract iridescent hummingbirds that dart about their canopies, to the deliciously tart P edulis that grows in great bowers over seemingly every fruit and veg garden, I adored them all.

Having seen so many shrugging off almost nightly frosts in high altitude villages, on returning to the UK I became desperate to see which cultivars were available here beyond the standard P caerulea that has dominated the British market for well over a century. I tried half a dozen forms, including officially the world’s hardiest species from North America, P incarnata, and soon realised there was a reason so few were available for outdoor growing here in Blighty.

Most, despite coping with frequent light frosts in perpetually cool, mild climates, can’t handle the prolonged cold for months on end that we get in Britain. The few that can need such rousingly hot summers to trigger them out of winter dormancy, they never have a chance to get going in our maritime climate.

Flash forward 20 years, after having long given up on my dream, I was frankly overjoyed to discover a host of new cultivars have been developed. With a few of these reliably hardy to about -8C, this makes them viable options for most British gardeners – and what dazzling forms they come in, too.

When I first spotted the giant lavender petals of ‘Betty Myles Young’ in my mate Rob’s garden, on blooms around twice the size of the standard P caerulea, I found it hard to believe they were not artificial. With petals swept elegantly back, as happens in many wild, Andean forms, it just screams “long lost jungle”. This is just one creation by the incredibly talented British breeder Myles Stewart Irvine, who also developed the astonishing ‘Snow Queen’, with a frilly crown of modified petals at its centre, which makes it look like a fascinator of the type you might see in a ballroom scene aboard a sci-fi film space ship.

Myles also magicked up ‘Damsel’s Delight’. This looks like a jacked-up version of the classic P caerulea, with much larger blooms and far more intense colours, as if retouched by too many Instagram filters, but in real life. If you are looking for a summer climber to transport you to the tropics, I beg you to treat a spare sunny wall to one of these.

Follow James on Twitter @Botanygeek