How to Plant, Grow, and Care for Passion Flower

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 Passiflora 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.

What is a Passion Flower?

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 them, like passion flower extract.

Native Area

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 ten 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. 

Characteristics

Its unique flowers are about three inches wide and have five petals accented with purple fringe. Their wonderful fragrance resembles that of carnations. The may-pop fruits are about two inches in size and ripen to yellow in summer. They taste like guava and should fall off the plant naturally in mid-to late summer before they are eaten.

The passion flower has large leaves with serrated edges that reach five or six 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, Passiflora edulis, Passiflora quadrangularis (giant granadilla), and yellow passion flower, known scientifically as Passiflora 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 Passiflora caerulea is preferable due to their size and availability. 

If you’re growing passion fruit, be aware of the passion flower species you’ve acquired. Passiflora biflora is an invasive species in Florida. Instead, choose a species like Passiflora incarnata or Passiflora 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.   

Planting

To plant passion flowers choose a sunny spot with well-draining soil. If starting from seed, lightly scarify the seeds by scratching the surface with sandpaper, then soak them in warm water for 24–48 hours before planting. Sow seeds directly into the soil or in pots indoors, covering them with about a quarter inch of soil.

For transplants or cuttings, dig a hole that is slightly wider and as deep as the root ball, about six to eight inches. Space the plants five to ten feet apart to allow room for the vigorous vines to spread. Install a trellis or other sturdy support nearby, as the vine can climb 20 feet or more. Water the plant thoroughly after planting and keep the soil consistently moist but not soggy. Adding two to three inches of mulch around the base helps retain moisture and reduce weeds.

How to Grow

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. 

Light

Six to eight hours of full sun is best for passion flower. Partial shade or afternoon shade may be required for plants in areas where 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 and prolific the plant is will factor into how well it can take being planted in direct sunlight. 

Water

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. 

Soil

A good quality garden or potting soil works for passion flowers. 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 passion flower vines prefer sandy, well-draining, fertile soil, they also grow in heavy clay soil. To develop your own mix, try ​two parts loam, two parts peat, and one part perlite or sand. Most species in the Passiflora genus appreciate neutral to acidic soils as well. 

Temperature

This plant is native to the southeastern US and is hardy in USDA zone 5 through 9. It handles lows down to 18°F (-8°C), 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.  

Fertilizing

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 slow-release fertilizer applied every four months during the growing season is more than enough.  

Maintenance

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 a third 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 a third 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.  

Propagation

It is possible to propagate via seed, but passion flower seed germination is difficult. The easiest ways to prop your passion flower vines are by layering and cuttings. Mound layer a vine by taking the leaves off of a woody stem and burying it under the soil. Place a stone or pin on top to keep it in place. Water the stem section well; it should root in two to three weeks. 

To propagate via cuttings, take six-inch 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 three months you’ll have new growth indicating your vines are ready for the garden.  

Common Problems

These hardy passion flower plants are native to at least a quarter of the US, and you probably won’t have problems beyond preventing its spread. Other issues could arise as well. 

Growing Problems

There could be situations where your passion flower vine doesn’t bloom. Overwatering prevents the formation of flowers on your vine. So does planting passion flowers 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 few 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 flowers. 

Pests

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 no larva are present. Consistent removal of fruit and encouraging predatory wasps prevent 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!

Diseases

Fusarium wilt is a fungal disease that causes the 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. Remove your plant and avoid planting in that area if it is affected.   

Cucumber mosaic virus usually spreads to passion flowers 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, it can be prevented 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 vine. 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