Passiflora caerulea, or the blue crown passion flower, is one of the best passion flower vines for growing indoors and will flower even when young. The 3-inch blooms, consisting of white petals and sepals topped with a ring of purple, white and blue filaments, are so intricate that they seem almost fake. The flowers are also fragrant, having a somewhat minty scent.
History of the Name
According to legend, the passion flower was named in 1620 by a Jesuit priest who came across it in its native tropical South American habitat. To him the flower's parts spoke of the crucifixion or passion of Jesus Christ. The five petals and five sepals stood for the apostles (not counting Judas and Peter); the three pistils represented the nails on the cross; the purple corona was Christ's crown of thorns.
The passion flower is a very quick-growing vine that can reach up to 20 feet in height. Under favorable conditions the plant may bear deep orange egg-shaped fruits which are edible. Some varieties are hardy in cooler climates, but blue crown passion flower is only hardy in zones 6 to 10.
Passion flower plants can be placed outside for summer, then trimmed back before being brought inside the house or greenhouse for the winter. They require at least 4 hours of bright, direct sunlight a day, throughout the year. Though the passion flower needs bright light, it requires cool temperatures. Using an oscillating fan can help provide the good air circulation the plant requires when it is kept indoors.
Keep the soil evenly moist during active growth. During fall and winter, allow soil to dry slightly between waterings. Repot every 2 years in the early spring, or simply topdress the plant. Keeping the plant slightly potbound will help encourage flowering. Feed with a high phosphorous fertilizer such as 5-10-5. An excess of nitrogen will stimulate growth of the plant's foliage while decreasing flowering.
Over 500 different species of passion flower exist. Ornamental varieties include Passiflora caerulea 'Constance Elliot', which has flowers of all white and blooms very freely. The red passion flower (Passiflora coccinea) has flowers of deep orange to scarlet. Passiflora x alato-caerula grows to only 6 feet and has fragrant pink blooms. Some species are grown especially for their fruit, which is often used as a flavoring in tropical punch.
When grown outdoors in a sub-tropical climate, passion flower vines require regular pruning to keep them under control. Stands of passion flower vines grow wild in some parts of southern Florida. The blossoms attract butterflies with their nectar, and also provide a food source for some butterfly caterpillars.