RHS Garden Rosemoor
Plant of the Month: October
Name: Erythrina crista-galli
Common name: Cockspur coral tree, cock’s comb, common coral tree, cry-baby tree
Family: Papilionaceae
Vital statistics
Height and spread: 6-9m (20-28ft) x 3-4m (10-12ft) as a tree, 1.5-2.5m (5-8ft) x 1-1.5m (3-5ft) as a shrub
Form: Deciduous tree or woody perennial
Soil: Fertile, moist but well-drained
Aspect: Full sun
Hardiness: Frost hardy (down to -5ºC, 23ºF), or if covered with a thick mulch down to -10ºC (14ºF)
Erythrina crista-galli @ Rosemoor
This plant, which grows at Rosemoor as a woody perennial, can be found in the sheltered microclimate of the Old Kitchen Garden to the rear of Rosemoor House, where the almost bizarre brilliant red flowers provide a superb splash of October colour.
Erythrina
This genus contains in excess of 100 species of deciduous, semi-evergreen, evergreen trees, shrubs, sub-shrubs and woody-based perennials, which are often spiny.
They are found in woodlands, thickets and open slopes in many tropical regions of the world.
Erythrina are grown for their pea-like, five-petalled flowers often as ornamental summer shade trees. The name Erythrina means coral tree from the Greek word for red, in allusion to the colour of the flowers.
The fruits are elongated pods, narrowed between the seeds.
Some species have medicinal properties, while others may be poisonous.
The seeds are used for necklaces.
Erythrina crista-galli
This species comes from East Bolivia to Argentina. In warm regions it is a deciduous tree but in cooler ones, a woody perennial. The name crista-galli means cock’s comb.
The branches are spiny and the leaves are leathery with prickly stalks, 30cm (12in) long, with triangular leaflets up to 10cm (4in) long. The longest leaflet is ovate-oblong in shape.
The flowers are deep red, 5-6cm (2-2.5in) long, borne in terminal racemes 30-60cm (12-24in) long from summer to autumn.
Erythrina crista-galli can be grown as a specimen plant in mild areas or as a potted greenhouse plant in colder ones.
Cultivation
Outdoors: grow in fertile, moist but well-drained soil in full sun. Prune in late winter or early spring when the plant is dormant, to remove any wayward or crossing shoots and maintain a healthy framework.
Under glass: grow in loam-based compost (John Innes No. 3) in full light. Water freely and apply a balanced liquid fertiliser monthly from spring to autumn. Prune to restrict size in late autumn.
Erythrina crista-galli is prone to two-spotted spider mite and mealy bug under glass.
Propagation
Sow seed at 21-24ºC (70-75ºF) in spring. Root softwood cuttings in early summer, or semi-ripe cuttings in late summer, both with bottom heat.