One of the most exotic flowers found in temperate regions is the passionflower, Passiflora incarnata. It is a native plant with a range that stretches from Central America and into the United States as far north as central Illinois, Ohio and Pennsylvania, which translates to USDA Zone 6 and sometimes Zone 5 with protection. There are other, more tropical species of passiflora, however this is the hardiest of the genus. The striking purple and white flowers that appear in late summer often reach three inches across and produce an edible fruit. It has several common names, but maypops tend to be the most often used. The name was thought to describe the popping sound that the fruit makes when stepped on, however that isn't the case. The Powhatan First Nation's word for the plant was mahcawq and over the years it was Anglicized to be maypop.
The passionflower grows in sunny meadows with well-drained soil. Full sun is best in the northern parts of its range, however, a little afternoon or dappled shade is good in the hotter, southern areas. It produces a scrambling vine that reaches up to 20 feet with side shoots and suckers where it is happy. The unique flowers bloom from mid-summer into fall and there is no chance for mis-identification. Nothing else looks like a passionflower.
Passionflower history and legends
Many people wonder how this plant got its common name, sometimes mistakenly assuming that the fruit is an aphrodisiac. That isn't the case. It seems that 16th century priests found that the construction of the flower was an excellent way of describing the details of Christ's Crucifixion, with the petals and sepals representing the disciples, the wavy rays the crown of thorns and the three anthers the nail wounds. This type of symbolism was a common practice as they spread Christianity, the shamrock in Ireland being another example. Among the New World peoples, the Inca called it the Vine of Souls and the Maya associated it with death and the underworld, so it wasn't a huge leap for the priests to convince the native peoples that the flower was sacred to Christianity as well.
Passionflowers and herbal medicine
Early peoples used the plant for medicinal purposes as well. Tea from the roots was a sleep aid, pain reliever and anti-inflammatory. They also gave babies the tea when trying to wean them from mother's milk. These properties have been verified by modern standards, however it is advised never use herbal remedies without consulting a medical professional.
Eat passion vine fruits
The fruit of the passion vine is edible and I can personally attest that it is quite tasty. I describe the taste much like a wild grape, sweet and tart at the same time, but also milder than a grape. The egg shaped fruits start out firm and green, ripening to a yellow color. When split open the hundreds of seeds are covered in a jelly-like substance. Eat them fresh, or cook them to release the juice. The juice is mixed into drinks or used to make jelly.
Passion vines as host plants
Butterflies and other insects like passionflower too. They are used as a host plant for many of the fritillary butterflies and ants set up housekeeping among the vines because of the extrafloral nectaries. This means that certain parts of the plant (such as leaf axils and ends of buds) other than the flowers produce nectar and ants find this a handy source of food. They guard the plants and even go as far as to push the caterpillars off the plants and eat the butterfly eggs to ensure their chosen plants aren't defoliated. There are a number of plants that produce nectar in this manner, peonies being another one that ants use this way.
Growing passion vine from seed
Growing passion vines is not hard. If you have a ripe fruit, break it open and scoop out the pulp. There is a jelly-like substance surrounding each seed. Remove this before planting because it is a germination inhibitor. The best way to to this is through fermentation. Many gardeners are familiar with fermenting tomato seeds and the process is the same. Put the pulp in a cup and set it on the counter for about 5 days. Mold will form and the jelly will start to dissolve. Pour the whole mess into a strainer and rinse under running water until the seeds are clean. Spread in a single layer to dry and store. Use the seeds within a year to ensure best the germination percentage. To help with germination, place in damp sand and place in the refrigerator for 12 weeks. This is called stratification and mimics the cold season. Then plant the seeds in damp seeds starting mix and place in a warm area. This lets the seeds think it is spring and they will germinate. Depending on how old the seeds are, they can take up to several weeks to germinate. If you don't want to go through the indoor process, simply sow the seeds outdoors in the fall and let nature take its course. The little vines should grow quickly and will most likely produce flowers their first year. Give them a sunny area and something to climb. Just remember that Passiflora incarnata is a short lived perennial and will likely live only three or four years, so make sure that new plants germinate every so often.
Growing passion vines in your temperate zone garden gives it an exotic appearance because most species are tropical and even though it is a native plant, many people have never seen them. Give visitors something to talk about and plant some of these beauties. Seeds and plants are widely available and make a great addition to most styles of gardens.