The passion flower is strange, wondrous, and native to the whole southeast United States. It’s a host for fritillary butterflies, and a great source of sweet, delicious fruit called may pops. It’s perfect for fenced and trellised areas of your landscape.
But P. incarnata has a tendency to get out of hand, and spreads rapidly if it’s planted in an area where it gets everything it needs to thrive. While this isn’t always an issue for gardeners, those who like a lazy garden may find it creeping into nearby beds.
All that being said, it’s a lovely vining perennial that provides stunning summer views year after year. Chances are you’ll love it once you add it to your garden.
Quick Care Guide
|Common Name||Purple passion vine, purple passion flower, passionflower, holy trinity flower, apricot vine, may pops|
|Scientific Name||Passiflora incarnata|
|Height & Spread||Up to 25 feet long and consistently spreads wider|
|Soil||Average garden soil or potting mix|
|Water||Regular water upon establishment, to no water after|
|Pests & Diseases||Spider mites, thrips, aphids, mealybugs, fruit flies, root knot nematode, fusarium wilt, cucumber mosaic virus, bacterial spot|
All About Passionflower Vines
Passifora incarnata is the scientific name for purple passion vine, purple passion flower, passionflower, holy trinity flower, apricot vine, and may pops. The purple passion flower is a fast growing vining perennial that reaches 20 feet or more. Both fruits and flowers are edible and many food items are made from it, like passion flower extract.
Its unique flowers are about three inches wide and have five petals accented with purple fringe. Its wonderful fragrance resembles that of carnations. The may pop fruits are about two inches in size and ripen to yellow in summer. These taste like guava, and should fall off the plant naturally in mid to late summer before they are eaten.
The Passionflower has large leaves with serrated edges that reach 5 or 6 inches long. They have three to five lobes and alternate along the stem. The flowers with their five petals bloom in early summer on the leaf stem. Passiflora incarnata needs something to climb on, and looks great on fences or a trellis. They are excellent for gardens designed to attract butterfly species. Excellent for butterfly gardening, they host the Gulf Fritillary and Variegated Fritillary butterflies and provide forage for carpenter bees in their native range.
The common passionflower is sometimes confused with other Passiflora species, like Passiflora caerulea, P. edulis, Passiflora quadrangularis (giant granadilla) and yellow passion flower, known scientifically as P. lutea. All of these Passiflora species are just as lovely as Passiflora incarnata, but their passion fruit and leaf shapes are different. Most passion flowers have edible fruit, but that of Passiflora edulis and P. caerulea is preferable due to their size and availability.
If you’re growing for passion fruit, be aware of the passionflower species you’ve acquired. Passiflora biflora is an invasive species in Florida. Instead choose a species like Passiflora incarnata or P. edulis, as neither is invasive, especially if you live in the subtropics. While Passiflora incarnata is not technically invasive, it spreads aggressively. Plant it where you can access it for heavy pruning.
The passion flower originates in the southeastern US and has been naturalized in Central and South America. It’s a flower of great significance to members of the Christian faith with its spikes representing the thorns of Jesus’ crown. Its five petals and sepals represent the 10 apostles who followed him, minus Peter, who denied Jesus.
It has been used in herbal medicines for ages. While it was sold commercially as a sleep aid, it was pulled from the market by the FDA due to concerns about its effectiveness. The growth of passiflora species is important to those who garden for hummingbirds, butterflies, and other pollinators.
Passiflora Incarnata Care
Now that we’ve discussed a bit about Passiflora itself, let’s discuss how to care for it and reap the benefits of its lovely fruit.
Sun and Temperature
6 to 8 hours of full sun is best for passiflora. Partial shade or afternoon shade may be required for plants in areas where the direct sunlight in late summer is scorching. I’ve seen vines growing out in the open exposed to full sunlight all day, though. So how established it is and how prolific it is will factor into how well it can take being planted in direct sunlight.
This plant is native to the southeastern US and is hardy in USDA zone 6 through 10. It handles lows down to 18°F, and highs in triple digits. As long as you give it time to get established, you’re gold! The root structure should have enough time to establish itself to survive through the hot summer and cold months, even when the showy leaves die away. If you’re growing in a container, bring it in when winter arrives.
Water and Humidity
Purple passion flower does best in containers when it is given a lot of water and then allowed to dry out before watering again. In the ground, that means local rain is often enough to keep it going. In times of drought, water a couple of times a week to keep the soil moist.
If you over winter the plant, gradually stop watering and trim it back when the foliage dies. In the spring when new growth appears, resume a normal watering schedule. Water in the morning before the sun is fully out. Moderate humidity is maintained when there is enough plant matter growing around the soil to provide it.
A good quality garden or potting soil works for passiflora. Make sure the root masses have access to well-drained soil. These vines have shallow roots. A thick layer of organic mulch helps the plant flourish through winter and emerge in early spring. Although passionflower vines prefer sandy, well draining, fertile soil, they grow in heavy clay soil too. To develop your own mix, try 2 parts loam, 2 parts peat, and 1 part perlite or sand. Most species in the Passiflora genus appreciate neutral to acidic soils as well.
Fertilizing Passion Flower
While fertilizing isn’t necessary, especially in its native range, you can provide high phosphorus fertilizers to help the passion fruit and its unusual flowers form. Do not overfeed as this will raise nutrient levels which attracts unwanted insects that feed on your vines. A 5-7-5 slow release fertilizer applied every four months during the growing season is more than enough.
Pruning Passion Flowers
Prune your plant just before spring arrives, or in early fall depending on the region you live in. To bring an older vine back to life or promote next year’s growth, pruning is necessary. You can also prune to train young passionflower plants on a trellis or other support. Prune dead plant material. Then, remove all stems except ones with plenty of buds. As a general rule, do not remove more than ⅓ of the plant, otherwise you risk killing it. If you know your vine dies back in colder months, cut it to the ground in early fall to ⅓ of its size.
You may wonder if deadheading the blooms is necessary. It is not! Flowers will bloom and fade on their own, and your passion plants will form fruits. Removal of the fruits before they fall to the earth can help control the plants’ spread, though they’re only ripe when they fall naturally. Pruning away suckers from the base of your vines prevents spreading too.
Passion Flower Propagation
It is possible to propagate via seed, but passiflora seed germination is difficult. The easiest ways to prop your passionflower vines are by layering and cuttings. Mound layer a vine by taking the leaves off of a woody stem, and burying it under soil. Place a stone or pin on top to keep it in place. Water the stem section well, and it should root in 2 to 3 weeks.
To propagate via cuttings, take 6″ sections from mature plants in fall. Root the cuttings in the soil you use to cultivate your vines. Using rooting hormone isn’t necessary, but it ensures each cutting roots. In about 3 months you’ll have new growth indicating your incarnata vines are ready for the garden.
Troubleshooting Passion Flower
These hardy passionflower plants are native to at least ¼ of the US, and you probably won’t have problems beyond preventing its spread. There are other issues that could arise as well.
There could be situations where your passion flower vine doesn’t bloom. Overwatering prevents formation of flowers on your vine. So does planting passion flower where it gets too much shade. Prune away woody branches to provide the plant with more sunlight, or prune plants around the planting area to open it up to more sunlight.
Because the passion flower is native in many parts of the US, it can take over a landscape in just a couple of years. Keep it in check by pruning aggressively in fall and winter, and by removing edible fruit from the plant as it ripens and falls. Letting it remain on the earth opens you up to a landscape dominated by the foliage of passion flower.
Common garden pests love to feast on the shrubs and vines of passion flower. Spider mites, thrips, aphids, and mealybugs suck the sap from members of the Passiflora genus, incarnata included. If you notice webs on your plant, small rice grain insects, congregating pear-shaped insects, or cottony masses, you might have any of the above. Most of the time, this showy plant is prolific enough to handle them.
If you want to treat them, wipe them gently off the vine. Because the plant is a host for native pollinator species like the gulf fritillary and variegated fritillary butterflies, applying insecticides isn’t recommended – even organic ones like neem oil can put feeding fritillary caterpillars at risk. Therefore, spot treatments and planting plant species that encourage predatory insects are better options.
Fruit flies may consume edible fruits and the flower petals of this native plant. As the adult fruit flies feed, they lay their eggs within the fruit. If you’re enjoying may pops in summer, inspect each carefully to ensure there are no larva present. Consistent removal of fruit, and encouraging predatory wasps prevents them.
Root knot nematodes may attack the tubers and kill the plant. Remove them by applying beneficial nematodes in two treatments in spring or fall, when the weather is temperate. Summer treatments will fail, and so will those in times when it’s too cold as good nematodes can’t survive in either condition.
Large orange caterpillars with black spikes eat the leaves of your passion fruit plant. These are the larval stage of either the variegated or gulf fritillary butterfly. These important pollinator species rely on passiflora species to pupate and metamorphose into butterflies. If you let them feed on your plants, they can take care of pruning for you!
Fusarium wilt is a fungal disease that causes lightening of the dark green leaves, and then subsequent leaf drop at the bottom of the plant. Eventually it travels to the roots and causes plant death. There is no control or cure for fusarium-affected passifloras, though there are many species bred for fusarium resistance. If your plant is affected, remove it and avoid planting in that area.
Cucumber mosaic virus usually spreads to passiflora from other affected plants. It causes mottled yellowing on the leaves of the plant around veins. It’s sometimes transmitted via aphid populations. While there isn’t a control for CMV, prevent it by controlling aphids. The best defense here is a healthy population of aphid predators.
Bacterial spot is present if you notice small angular spots on the leaves of your passiflora. These have a yellow ring around them and spread if the bacteria is allowed to proliferate on your plant. There is no treatment or cure, but there are disease resistant varieties of P. edula and P. caerulea.
Frequently Asked Questions
Q: Is Passion flower poisonous to humans?
A: The unripe fruit and the leaves cause nausea and vomiting in humans. Stick to consuming ripe fruit and using flowers in tea.
Q: Do passion flowers come back every year?
A: Especially in zones 6 through 10, your passionflower vine will die back in cold seasons and return in spring.
Q: Is Passion flower a drug?
A: It has been used as a sedative in commercial and herbal settings, but its commercial use was retracted by the FDA due to concerns about effectiveness and safety.
Q: Is passion flower poisonous to dogs?
A: The flower is not poisonous to dogs, but the leaves and unripe fruit are.
Q: Should I deadhead passion flowers?
A: No need. The flowers drop naturally after they’ve bloomed.
Q: Are passion flowers invasive?
A: In its native range it can be aggressive. Prune and maintenance your passifora effectively, and you won’t have to worry about invasions.
Q: Will passion flower survive winter?
A: While it will return in spring, the vines die back in winter. The roots survive through the cold.
Q: Do bees like passion flower?
A: Yes. Bees, butterflies, and hummingbirds are attracted to this plant.