The genus Passiflora includes numerous species of flowering vines commonly called passionflowers or "Maypops" for the way they pop out of the ground in May. According to The University of Maryland Medical Center website, passionflower is "a perennial climbing vine with herbaceous shoots and a sturdy woody stem that grows to a length of nearly 10 meters (32 feet)." Although many passionflowers are tropical, you can grow some in northern climate zones.
Location and Soil
Plant a purchased Passiflora vine in spring in a protected area that has well-drained soil and receives full sun. If you dig a 1-gallon bucket full of organic compost of any type into your planting hole, your Passiflora will grow well. Also, keep the soil evenly moist throughout the summer growing season.
Give your Passiflora a balanced plant food with an N-P-K ratio of 10-5-20 in early spring, and then repeat your application after six or eight weeks have passed.
Control Insect Pests
Caterpillars can attack some species of Passiflora. To keep them under control, hand pick and destroy these crawling insects or dust your vine with Bacillus thuringiensis (Bt), a naturally occurring soil bacterium sold in nurseries. Keep white flies under control by hanging yellow sticky traps around your Passiflora vine. Also, keep weeds pulled or cut short around your plant. If white flies are a continual problem for your Passiflora, consider laying a shiny material such as aluminum foil on the soil around your plant---it will scare away white flies.
Because passionflowers grow on a vine that can reach over 30 feet in length, keep your plant tidy and compact by providing it with an arbor, fence or trellis to climb. You can also prune the vines to keep them from overtaking your garden. However, if you grow a fruiting variety of Passiflora, wait until after you harvest the tangy fruit before you cut your vine.