Passiflora caerulea (Blue passion flower) is a Climber which grows to a height of 10 m and a width of 10 m . It has a fast growth rate. It has a hardiness rating of 7 and is quite resilient to frost.
Blue passion flowers will flower from December to March. The seeds ripen from March to May.
The flowers from this plant are hermaphrodite (has both male and female organs) and they are pollinated by bees.
Central and Western S. America - Brazil.
How to Grow Passiflora caerulea
Blue passion flowers will grow in light (sandy), medium (loamy), hard (clay) soil. It is important for the soil to be well drained. Blue passion flower prefers moist soils.
Blue Passion Flower Ideal Planting Locations
Blue passion flowers should not be planted in shady areas.
Cultivating Passiflora caerulea
Requires a well-drained soil with plenty of moisture in the growing season, otherwise it is not fussy. Dislikes highly alkaline soils. Hardy to about -15°C, if plants are cut down to the ground by frost they can regenerate from the base. Very fast growing.
Roots of outdoor grown plants should be restricted to encourage fruiting. Plants produce tendrils and climb by attaching these to other plants. The plant has a very long flowering period, from early summer to early autumn, though individual flowers only live for about 48 hours.
The flowers are open all night and start to close in the morning. The flowers are delicately scented. The cultivar 'Constance Elliot' is more fragrant. If fruit is required, especially when the plant is grown indoors, it is best to hand pollinate using pollen from a flower that has been open for 12 hours to pollinate a newly opened flower before midday.
The flowers open in sunny weather and do not open on dull cloudy days. Fruit is only formed after long hot summers in Britain. Plants are very tolerant of pruning and can be cut back to ground level if required to rejuvenate the plant.
Any pruning is best carried out in the spring. Plants in this genus are notably resistant to honey fungus.
Passiflora caerulea Edible Uses*
* See disclaimer
Fruit - raw or cooked. The unripe fruits are cooked, whilst the ripe fruits are eaten raw or made into a refreshing drink. The flavour is not very desirable. The fruit is about 6 cm long and 4 cm wide, it is partly hollow and contains a small amount of pleasant acid-tasting pulp surrounding a large quantity of seeds. The flowers can be made into a syrup.
Passiflora caerulea Propagation
Pre-soak the seed for 12 hours in warm water and then sow late winter or early spring in a warm greenhouse. If sown in January and grown on fast it can flower and fruit in its first year. The seed germinates in 1-12 months at 20°C.
Prick out the seedlings into individual pots when they are large enough to handle. If you are intending to grow the plants outdoors, it is probably best to keep them in the greenhouse for their first winter and plant them out into their permanent positions in late spring or early summer, after the last expected frosts.
Mulch the roots well in late autumn to protect them from the cold. Cuttings of young shoots, 15 cm with a heel, in spring. Leaf bud cuttings in spring. Cuttings of fully mature wood in early summer. Takes 3 months. High percentage.
This plant can be used as a rootstock for some of the less hardy members of this genus, conferring on them an additional cold tolerance. Be careful that root suckers do not take over from the grafted plant.
Passiflora caerulea 'Constance Elliot'
- Trees and Shrubs Hardy in Great Britain. Vol 1 - 4 and Supplement. Author: Bean. W.
- The New RHS Dictionary of Gardening. 1992. Author: Huxley. A.