Commonly known as the Scarlet Passion Flower, Passiflora coccinea is a fabulous lush evergreen climber that is grown for its spectacular, large red flowers, rather than for its fruit.
The vivid scarlet-red flowers grow up to 12cm (5in) wide with scarlet red sepals and petals, and white and deep purple corona filaments. The plants can have flowers for much of the year but are seen at their peak in summer and autumn.
The flowers are followed by stripped edible fruits that initially look like dwarf water-melons. Rounded and relatively large, around 5cm (2in) in diameter the fruits first appear green, striped and mottled, and become golden yellow when ripe.
Passiflora coccinea is native to South America. The plants require a minimum temperature of 4°C (40°F) and need to be protected from frost or planted in frost free areas. They may be grown as a houseplant in a sunny south-facing window and are ideally suited to glasshouse or conservatory conditions.
Sowing: Sow indoors at any time of year
Prior to Sowing, lightly sandpaper the seeds on one or both sides using fine sandpaper, then soak them in tepid water for 24 hours. Soaking is beneficial in two ways; it can soften a hard seed coat and also leach out any chemical inhibitors in the seed which may prevent germination. 24 hours in water which starts off hand hot is usually sufficient. If soaking for longer the water should be changed daily. Sow 2 to 5mm deep in peat or soil based seed compost. Once sown, the compost must remain moist. Cover the top of the pot with clear plastic so the humidity will remain high.
Germination of Passiflora can occur in weeks or take several months. If your home is on the low side of 20°C (68°F), your seeds will benefit from bottom heat with an electric soil warming cable kit, or a heating mat. It will stimulate early growth, and help seeds to germinate and cut the germination time by half. Temperature is probably the most important factor in germination, ideally at 20°C (68°F) for 16 hours and 30°C (86°F) for 8 hours each day. If this is not possible, then a constant temperature of 26°C (79°F) is advisable.
When you see some tiny plants starting to sprout, open the top of the pot, a little each day, so that the new seedlings don't go into shock from the humidity being lowered too quickly. Prick out each seedling as it becomes large enough to handle, transplant into 7.5cm (3in) pots and pot on as required. These plants have very fragile roots and should be handled with care when potting on.
Grow on under glass in loam-based potting compost in full light with shade from hot sun. You may need to water your plants on a daily basis during the hottest summer months. During the winter the roots should be kept moist, but as growth will be much slower you will probably only need to water once a week, depending on growing temperature. Fertilise at least once every two weeks in the growing season.
If planting passion flower outdoors, gradually acclimatise to outdoor conditions for 10 to 15 days before planting out, space 30cm (12in) apart. Plant out seedlings when they are about eight inches high (20cm). If you wait too long and they are much bigger than that prune them back as you plant them out. It helps reduce moisture loss while the root system settles in. The plants like a position in full sun and will scramble over trees and shrubs to get it, they are best in a position with shelter from cold, drying winds. If growing passion flower in a south-facing glasshouse or conservatory, shade from direct sunlight may be needed to prevent the leaves from scorching. They like moderately fertile, well-drained but reliably moist soils, they will thrive in any soil type and are not fussy about acidity or alkalinity.
Although Passiflora is a self-clinging tendril climber, they benefit from training, which produces a more attractive plant than if left alone to scramble. They can be trained to grow up and over a trellis, a fence, a water tank or a shed, anything will do.
Container grown plants:
Passion flower can also be grown in a container. Use either John Innes No 3 potting compost, or good quality multipurpose compost.
If the pot is too large or they have an unrestricted root run then the whole plant will simply get bigger but it will refuse to flower and produce fruits. By limiting the pot size you are limiting the ability to grow and this is seen as a threat, so the natural mechanism is to produce seeds for the next generation. A suitably sized pot for an adult plant would generally be 30cm (12in) in diameter.
Water passion flowers freely during the growing season, especially container grown specimens to ensure that they don’t dry out. Water them more sparingly during the winter, allowing the compost surface of container grown specimens to begin to dry out between waterings.
When established, and without care, the passion flower can easily overtake other plants, shading them from sun. Pruning is a must to keep the vine healthy, enable air to circulate through the foliage, keep the plant within bounds, and stimulate vigorous new growth to enable flowering and fruiting. Passion flowers only set fruit on new growth.
In the tropics, passionflowers are pruned as soon as they have finished fruiting. In cooler climates you can prune in early spring. Cut out everything that is dead or weak. Shorten the side shoots to within three to four buds of the permanent framework of branches. This induces more compact growth and promotes the formation of flower buds in the shortened shoots.
Fences or trellis work or scrambling up trees and shrubs. Patio/Container Plants, Sub-tropical or Wall-side Borders. Container, Indoor / Greenhouse Plant
Passiflora coccinea is native to South America; Bolivia, Brazil (Amazonian), Colombia, French Guiana, Guyana, Peru, Suriname and Venezuela.
Its beautiful dark red flowers share similarities with those of Passiflora vitifolia, the only true red flowering plants in the Passifloraceae.
The fruit is both eaten and juiced; passion fruit juice is often added to other fruit juices to enhance aroma.
The genus name Passiflora is derived from the Latin passio meaning ‘passion’ and flos meaning ‘flower, in reference to parts of this plant seemingly representing aspects of Christ. The Passion flower symbolises spirituality. 16th Century missionaries in South America named it the passion flower because they believed it symbolised the death of Christ - the sepals and petals represented the disciples; the double row stood for the crown of thorns, and the stamens stood for the wounds.
The species name coccinea is derived from the Latin word meaning 'deep red' and refers to the scarlet red colour of the species. (The way to remember is to think of the cochineal beetle, famous for giving us a red dye).
The National Collection:
The National Collection of Passiflora is kept at - Lampley Road, Kingston Seymour, Clevedon, North Somerset, BS21 6XS, UK.
Tel : (0044) 01934 833350. Visitors are welcome but please call before visiting to confirm the opening times.
- Additional Information
Average Seed Count 10 seeds Family Passifloraceae Genus Passiflora Species coccinea Common Name Scarlet Passion Flower, Red Granadilla Hardiness Tender Perennial Flowers Scarlet Natural Flower Time At their peak in summer and sutumn Height 4.5 to 9 metres (15 to 30ft) Position Full Sun Notes Vine/Climber