The passion flower (Passiflora incarnata) blooms with a gorgeous flower pollinators love. Sarah Jay will go through the detailed guide and best-growing tips to get the most out of this rampant vine.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.
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.
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
This flower prefers full sun exposure with at least 6 to 8 hours of sun per day. 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
Close-up of a watering can pouring water onto young plants with elegant, arching stems and smooth, rounded green leaves with delicate veins.
Ensure the soil has dried out before watering again. 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
Use a good quality garden or potting soil that drains well. 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
The flowers will thrive in hardiness zone 6 to 10. 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
Close-up of a woman's hand with NPK fertilizers on a blurred background of a pink bag of fertilizers. Fertilizers are granular and consist of many small round balls of a delicate pink hue. They can benefit from a high-phosphorus, slow-release fertilizer every 4 months. 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
Pruning helps promote new growth. 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
This perennial can be propagated using its cuttings or seeds, which is often more difficult. 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.