Passiflora coccinea Seeds | Red Passion Flower

Dark brown, flattened Red Passion Flower seeds with a pitted surface, on a plain background — Red Passion Flower (*Passiflora coccinea*): Passifloraceae, native to the riverbank thickets of northern South America.

LATIN NAME: Passiflora coccinea

COMMON NAME: Red Passion Flower

Plant Profile

Red Passion Flower is a vigorous climber with slender, grooved stems and glossy, oblong leaves, climbing by tendrils to four or five metres. The flowers are the attraction: brilliant scarlet, about eight centimetres across, with a shallow cup of red petals and sepals and a corona of short filaments banded in red and white around the central column.

It comes from the Guianas, Venezuela, Colombia, Peru and northern Brazil, where it scrambles over riverbank thickets and forest edges in the humid lowlands. In the tropics it flowers almost continuously; in cooler gardens it blooms in late summer and autumn. The leaves are dark green above, paler and slightly hairy beneath, and they hang from the tendrils in a way that gives the vine a dense, curtain-like look.

Science & Biotechnology

The species is pollinated by hummingbirds, and its flower structure reflects that: the red colour, the shallow cup and the large amount of nectar all suit a bird that hovers and probes. Many populations are self-incompatible, so a single clone may flower freely without ever setting fruit.

Passiflora is a large genus with a well-studied chemistry, and P. coccinea has been examined for the flavonoid and cyanogenic glycoside content typical of the family. Its leaves carry extrafloral nectaries on the petiole, which attract ants that defend the plant against herbivores, a relationship much studied in tropical Passiflora.

Uses & Benefits

In the garden it is grown for its flowers, on a warm wall, a pergola or in a large conservatory, where the scarlet blooms are visible from a distance. It is fast-growing and can be cut back hard in spring, which makes it manageable in a small space.

Unlike its relative Passiflora edulis, the fruit is not worth eating: it is small, green and seedy. The foliage is eaten by heliconiid butterfly larvae in the neotropics, and in a tropical garden the plant will be found by them. In Brazil it is planted over fences and pergolas, where the weight of the growth is carried by the support rather than by the plant.

Growing from Seed

Sow in spring at 22 to 25 °C in a free-draining mix, covering the seed lightly. Germination can be slow and uneven, anything from three weeks to three months, and scarifying the seed or soaking it overnight shortens the wait.

Plant out in a warm, sheltered spot with a strong support and deep, moist but drained soil. Water regularly in the growing season and feed lightly; too much nitrogen gives leaves and no flowers. In cool climates grow it in a pot and overwinter it under glass at a minimum of 10 °C. In a conservatory, keep the roots confined to a large pot and water freely from spring to autumn, then cut back on water in winter.

Our Take

A scarlet climber for a warm wall, flowering for months where it is happy. Easy from seed and easy to keep in check with a hard spring prune.

Herb Seeds