Passiflora incarnata, commonly known as maypop, purple passionflower, true passionflower, wild apricot, and wild passion vine, is a fast-growing perennial vine with climbing or trailing stems. A member of the passionflower genus Passiflora, the maypop has large, intricate flowers with prominent styles and stamens. One of the hardiest species of passionflower, it is both found as a wildflower in the southern United States and in cultivation for its fruit and striking bluish purple blooms.

The stems can be smooth or pubescent; they are long and trailing, possessing many tendrils. Leaves are alternate and palmately 3-lobed and occasionally 5-lobed, measuring 6–15 centimetres (2.4–5.9 in). They have two characteristic glands at the base of the blade on the petiole that secrete drops of sweet nectar. Flowers have five bluish-white petals. They exhibit a white and purple corona, a structure of fine appendages between the petals and stamens. The large flower is typically arranged in a ring above the petals and sepals. They are pollinated by insects such as bumblebees and carpenter bees, and are self-sterile. The flower normally begins to bloom in July.

The fleshy fruit, also referred to as a maypop, is an oval yellowish berry about the size of a hen egg; it is green, though it may become yellow-green to yellow-orange as it matures. Like other passifloras, the pulp is gelatinous and encases the seeds. The color of the pulp is originally white and becomes a dull yellow when ripe. The seeds are black and approximately 5 mm in size. As with other passifloras, it is the larval food of a number of lepidoptera species, including the zebra longwing, the Gulf fritillary, the crimson-patched longwing, the Julia, the Plebeian sphinx, and the variegated fritillary. In many cases its fruit is very popular with wildlife. The egg-shaped green fruits ‘may pop’ when stepped on. This phenomenon gives the P. incarnata its common name, as well as the fact that its roots can remain dormant for most of the winter underground and then the rest of the plant “pops” out of the ground by May, unharmed by the snow.

The maypop occurs in thickets, disturbed areas, near riverbanks, and near unmowed pastures, roadsides, and railroads. It thrives in areas with plentiful sunlight. It is not found in shady areas beneath a forest canopy.

The Cherokee in the Tennessee area called it ocoee; the Ocoee River and valley are named after this plant, which is the Tennessee state wildflower. The local salamander Desmognathus ocoee in the Tennessee region is also named after the Cherokee word for P. incarnata. For thousands of years the maypop was a staple food and medicinal plant for the Cherokee and to this day it is a revered piece of their heritage. This, and other passionflowers are the exclusive larval host plants for the Gulf fritillary and non-exclusive for the variegated fritillary butterflies.

II. How to Grow and Care

Sunlight

Purple passionflowers thrive in full sun but can also tolerate a part shade position.

Temperature and Humidity

These tropical-looking flowers are surprisingly cold-tolerant. Plant your purple passionflower in well-drained soil; the roots should be hardy down to around -5 degrees Fahrenheit. While the top growth dies off in these freezing temperatures, the plant will stay healthy if you mulch the roots. In warmer climates, this evergreen remains woody.

Watering

This climbing vine can handle drought conditions but keep the soil consistently moist for the best chance to appreciate the beautiful blooms. Slow, deep watering at the root level is best. Applying a few inches of loose mulch at the roots can help to retain moisture, especially when conditions are dry. Just make sure the mulch doesn’t press up against the plant stem.

Soil

Purple passionflowers aren’t fussy regarding soil and adapt well to most types (including extremely poor soils), provided they are well-drained and moist. It might even get a little out of control in highly fertile soils.

Fertilizing

Regular light feeding helps ensure your purple passionflower blooms prolifically. Select a fertilizer that isn’t too heavy in nitrogen; otherwise, growth will focus on the green foliage rather than the flowers. Fertilize in the early spring before the emergence of new development. Once the flowers appear, feed at least once a month or more up through early fall. For the amounts to use, follow product label instructions.

Pruning

You won’t need to prune purple passionflowers regularly. To encourage a full, bushy appearance and prevent your climbing vine from looking straggly, pinch back the plants in their first growing season. Cut back the top growth annually in cooler climates where it’s marginally hardy, and treat it as a herbaceous perennial rather than a woody evergreen.

Because flowering occurs on new growth, pruning should be done in late winter or early spring to ensure new blooms appear in abundance later in the spring.

This twining vine is ideal for growing up against trellises, outbuilding walls, or fences. Because it attaches with tendrils, it won’t cause damage to brickwork the way plants with aerial roots, like ivy, can. However, it still produces flowers even if it is sprawling rather than climbing.

To encourage flower and fruit production rather than excess foliage growth, try restricting the development of the spreading root suckers. Growing it in a container is a good option.

Propagation

It’s possible to propagate purple passionflowers via various methods, including taking softwood stem cuttings, tip layering, and growing from seed.

To propagate from stem cuttings, try following the steps below:

In the spring, select a 6-inch cutting from a young shoot with leaf buds (you can also take woody cuttings in early summer).
Remove any leaves at the base of the cutting.
Put the base of the cutting into a well-drained potting mix at a depth of around 1 inch.
Moisten the potting mix and cover the pot with plastic with a couple of air holes.
Keep the plant warm, moist, and out of direct, intense sunlight.
It typically takes a few weeks for the cutting to start taking root.
Once the roots have adequately taken hold, you can transplant it to its outdoor location.

If you want to create a new plant in the same location as the original, you can try propagation by tip layering. This involves bending a stem of the existing plant to the ground, covering it in soil, and waiting to see if a new shoot will develop. Trying this method in late summer or early fall is best, and following the tips below can help maximize the chances of success.

Remove any leaves and nodes before pushing a vine tip into the soil for a smooth finish. Foliage buried in the soil can lead to bacterial problems.
Make a dip in the soil, place the tip into this space, and then cover it with soil.
You might need to weigh down the tip with a small rock or garden anchor pin to stop it from popping up and losing contact with the soil.
When the tip is well-rooted (it should stay in the ground when you tug on it), it should create another plant in the same place. Alternatively, you can dig it up and detach it from the original plant to transplant it to a different location.

Pests and Diseases

Common 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 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.

Common Diseases

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.

Potting and Repotting

You can successfully grow passionflowers in containers, where they will offer you the convenience of being able to move them to a sunnier site or even bringing them indoors for the winter. Additionally, growing in pots prevents passionflowers from spreading uncontrollably.

To successfully pot your passionflower, use a potting soil rich in nutrients, and make sure the pot (of any material) has several large drainage holes at its base. Keep the soil moist, but don’t allow the roots to sit in water. Plants grown in containers will need more regular feedings since they are watered more frequently and nutrients typically rinse out as the soil drains.

Because purple passionflowers are such heavy feeders, even with fertilizers, your plant will exhaust the nutrients in the pot after a few years.

Repot in a container at least a few inches bigger than the current one. Make sure the pot has good drainage holes and that the medium you use is fertile and well-drained.

Overwintering

You can overwinter your plant outdoors down to USDA zone 5 or 6 if you provide ample winter protection. If it’s in a container, move it up against a building as a windbreak. Also, wrap the container in a blanket or burlap. If it’s in the ground, add two to three inches of wood or leaf mulch around the plant and leave space around the main vining stem. Withhold fertilizer for the two months leading up to the cold season.

Bring the plant inside if it’s too cold for your plant outdoors. Allow the plant to enter dormancy by placing it in a basement or garage that doesn’t drop below freezing. Do not expose it to the sun. Only water the plant once a month.

You can also treat the plant as a houseplant, placing it in a window to get at least six hours of sunlight, keeping it at a warm ambient temperature, and feeding it as normal. However, this is a vining plant that needs a trellis. To keep it manageable, trim it and give it a climbing structure. Water it less frequently than in summer, perhaps once a week or every 14 days.

III. Uses and Benefits

Medicinal uses

Historical uses and folk medicine

Historically, the plant has been used as a herbal medicine.

Passionflower is included in pharmacopeias, such as the European and British Pharmacopoeias in which the dried aerial parts of the plant are mentioned. In North America and South America, tea made from the roots is used as a tonic. The U.S. Food and Drug Administration withdrew approval of its marketing because manufacturers did not submit any evidence regarding its safety and effectiveness.

Culinary uses

Passionflower has culinary fruits that may be used for jams, jellies and desserts. The juice is a favorite flavoring in drinks. It can be used as a fresh substitute for its commercially grown South American relative, Passiflora edulis, a related species with similar sized fruit. The fruit can be eaten by hand; it has a mildly sweet-tart taste similar to an apricot and a pleasant scent when fully ripe. The Passiflora family have aromatic, sweet fruit that make it highly appreciated for fresh consumption and as a flavoring aid.