Also known as Passiflora, passion flower vines are among the most beautiful climbing plants you can grow, with their instantly recognizable flowers, with a long flowering season.
They will quickly cover any vertical surface, providing a great screen for any bare fence, wall, or trellis.
Not sure if the passion flower vine is for you? Here’s everything you need to know.
At A Glance: What You Should Know About Passion Flowers
There are over 500 different species in the Passiflora genus, most of which are vines, but you can also get shrubs or trees, too.
These plants are easy to grow, as long as you pick one that’s suitable for your climate.
If you live somewhere that gets cold winters, it’s worth trying Passiflora caerulea, which is fairly resistant to cold temperatures or consider growing passion flowers in a greenhouse or conservatory instead.
Most passion flower species are evergreen, which makes them very attractive options for having vertical flowers and leaves all year round.
How To Grow Passion Flowers
Passion flowers are very difficult to grow from seed, and this is made a more unappealing option when you know that plants can take more than ten years to produce their fantastic flowers.
The good news is that you can readily buy established passion flowers that have been grown in pots, and should flower within their first year or two of planting.
If you prefer, you can take cuttings from an existing plant, and this will also speed up the time it takes to flower considerably, as long as the original plant is already mature enough to produce flowers.
Make sure to take cuttings in the first few weeks of spring, taking several to boost your chance of success. Choose healthy vines, and make sure the cutting has a node.
Cuttings that are about 6cm long will do, just remove any bottom leaves and tendrils, and pop the cutting into decent compost. To make sure the cuttings root, it’s a good idea to use a heated propagator.
Once you see new growth, this is the plant telling you it has established roots.
Sunlight And Position
Passion flowers like a sheltered position, away from strong winds and cool temperatures. Give them full sunlight, preferably against a sunny wall so that the heat radiates back to the plant.
This will also give the plant some protection from frost.
If you are training your passion flower vine to climb a wall, use galvanized wire to help support the vines, and encourage them to grow up the wall.
You can also plant them up an obelisk, trellis, or pergola, as long as wherever you pick has plenty of sunlight and enough warmth.
If the soil in your garden is very heavy, it’s worth improving how well the soil drains by putting some horticultural grit into the planting hole before you put the passion flower in.
You can also grow them in containers if you prefer, but you will need to water and fertilize them more often than if you plant them in the ground.
Watering And Feeding
When planting a passion flower vine for the first time, water it immediately. After this, water it once or twice a week in the growing season when it is dry, depending on your climate.
If the soil gets too dry for the vine, the plant will start to drop buds.
Make sure you hold off on watering potted passion flower plants during the winter, as they won’t need as much water as they do in the growing season.
These plants don’t usually need extra fertilizer, unless you are growing them in pots, or they look like they need it. In which case you should use a liquid fertilizer, every four weeks or so.
Ensure that you don’t feed the plant at all during the winter, to allow the plant to go dormant.
How To Train Passion Flowers
It’s worth knowing that while these plants will need a little attention, to begin with, you won’t need to train the mature vines once established in your garden, as they produce tendrils that help support the plant.
When you first start, however, you will need to tie in the plant to your support, making sure that the vines you tie in can still move with any winds, and aren’t too constricted.
How To Prune Passion Flowers
Passionflower plants need an occasional haircut, but nothing major. Trim back the flowers after they have finished, making sure to cut back to healthy buds.
If you find that the plant has gotten unruly, it’s best to wait until spring to give them a proper chop.
Make sure you cut back any leaves or stems that have been damaged by cold in the spring.
Pests And Diseases To Watch Out For
In terms of disease, fungal infections can be a problem for passion flowers. Black splotches may appear on the leaves or even mold.
The way to prevent fungal diseases is to make sure that the plant has plenty of air circulation and space to grow.
Also, avoid watering the plant from overhead, always do so at the base, and make sure that the plant is in full sunlight.
Cucumber mosaic virus is also a problem with passion flower plants, which causes the plants to take on a sickly tinge of yellow, stunting the plant’s growth, and distorting fruit and flowers.
If your plant has caught this disease, it will need to be destroyed and disposed of carefully to stop it from spreading to your other plants.
When it comes to pests, aphids, whitefly, red spider mites, and mealybugs can be a problem, especially if you grow it under glass such as in a greenhouse or a conservatory.
The best way to prevent pests is to keep the plant as healthy as possible, which will improve its resistance. Check the foliage, especially the undersides, every few weeks to catch an infestation early.
How To Overwinter Passion Flowers
It’s worth noting that the majority of species belonging to the passion fruit family are native to tropical areas, in particular central and South America, so if you live somewhere that gets cold winters, you will have to protect these plants.
A good way to avoid losing passion flowers during the winter is to be clever about where you plant them.
Grow them up against a sheltered wall that gets full sunlight for most of the day, preferably a house wall, and this will help keep the plant from the worst of the frosts.
However, you should take cuttings from your plant in summer, so that if you do lose the original in a very fierce winter, you will still have more to plant out.
Passion Flower Varieties You Should Consider Growing
Perhaps the most widely grown cultivar is Passiflora caerulea, which produces large white blooms with purple, blue, and white filaments in the center, followed by orange fruit.
In the right place, it can reach 12 meters tall, spreading to 4 meters wide.
If you want flowers that are unusual even for passion flower plants, this variety is for you. It produces long, light pink flowers in summer, reaching an eventual height of 4 meters.
One thing to note about this cultivar is that it won’t stand cold temperatures, so grow it in a greenhouse if you live somewhere that gets cold.
Hailing from Australia, Passiflora aurantia reaches a maximum of 2 meters tall in the right conditions, producing fabulous pinkish-orange tubular-shaped flowers in summer, which change color over time.
These flowers emerge in a light cream and deepen into orange, and finally mature into a dark red.
These are followed by purple fruits, which are inedible to us but still put on a dramatic display.
Reaching between one and two meters tall, this type of passion flower remains fairly compact and very easy to manage, perfect for smaller gardens.
It helps that it produces many brilliant red flowers in summer.
A relatively new discovery is the citrine passion flower, which is not a hybrid at all, but was discovered growing wild in Honduras.
It features small, lemon-yellow flowers, felted green leaves, and a long flowering season, capable of producing blooms for up to 10 months in the right conditions.
It’s worth pointing out that this species is usually grown as a houseplant, as it cannot tolerate very cold temperatures.
A species that is difficult to find outside specialist retailers, this particular plant is still worth mentioning as it is absolutely beautiful. There have been a few hybrids made from this species, including ‘Anastasia’ and ‘Grand Duchess’.
Passiflora gritensis hails from Colombia and features large flowers with bright pink petals, each featuring a white stripe along the midvein.
Passiflora incarnata ‘Incense’
The result of crossing Passiflora incarnata and Passiflora cincinnata, this is a striking plant that blooms with bowl-shaped purple flowers, each one capable of reaching 12cm wide.
Each bloom also features prominent filaments and is followed by yellow fruits which are edible but quite acidic.
It helps that this is one of the hardiest varieties you can get, capable of withstanding temperatures as low as 0°F (-17°C), so you don’t have to worry too much about overwintering it unless you live somewhere that gets colder than that!
It is worth noting that sometimes the vine itself will die back for the winter, but new growth will emerge from the ground in spring.
Passiflora vitifolia ‘Perfumed Passionflower’
Producing fantastically bright red flowers, the perfumed passion flower is a worthy option for any garden.
The name refers to the fruit, which has a strong fragrance. It’s worth noting that when the fruit falls off the plant, they are extremely tart, but if you leave them to ripen on a windowsill, they sweeten over time.
Passiflora antioquiensis ‘Vanilla Passion Fruit’
If you want the largest flowers that these plants can offer, this particular species is for you. Each flower can reach 15cm wide, producing bright red flowers with purple corollas.
These flowers are soon followed by banana-shaped fruit.
Passiflora foetida ‘Stinking Passionflower’
You might question why we would put this particular variety on this list. Still, it’s one worth knowing.
The stinking passion flower will only emit its rotten smell if the flowers are disturbed, but it’s worth mentioning that it is classed as invasive in several areas, so check with your local authority before planting.
With the disclaimer out of the way, this passion flower vine produces brilliant white flowers with a hint of maroon in the heart of each flower.
Other Things To Consider When Growing Passion Flowers
Are Passion Flowers Edible?
No. However, you can eat the fruit, provided that you grow a variety that’s been specifically cultivated to produce edible fruit. You can also use the pulp in drinks and jams, too. Otherwise, don’t eat them!
How Long Do Passion Flowers Last?
Depending on the cultivar, some passion flower plants produce blooms that only last for a single day, while others can flower for up to several days.
The good news is that most varieties will flower from the earliest weeks of summer well into fall if the weather conditions allow.
Are Passion Flowers Invasive?
Some types can be invasive, depending on where you live and what type you choose.
In particular, Passiflora caerulea has a very vigorous growth habit and can produce suckers that are several meters away from its original parent plant!
So it’s always worth checking what type would be suitable for your area before you buy.
Passion flowers are among the most captivating flowering vines you can grow, as well as the likes of clematis and climbing roses.
While they are not tolerant to frost, if you pick the right species and position, they are not difficult to overwinter and should survive in colder areas.
You can even grow passion flowers as houseplants, though some species are more suited to this than others.