Plant of the Week: Cotinus Coggygria ‘Royal Purple’

By Davis Landscape Architecture @DavisLandArch

Cotinus coggygria 'Royal Purple' autumn leaf (12/11/2011, Kew, London)

Position: Full sun to partial shade

Flowering period: Summer

Soil: Moist, well-drained

Eventual Height: 4m

Eventual Spread: 4m

Hardiness: USDA Zones 4a – 8b

Family: Anacardiaceae

Cotinus coggygria ’Royal Purple’ is a deciduous open shrub with a bushy growth habit. The dark red/ purple leaves are 3 – 8 centimeters long with a rounded oval shape and have a waxy glaucous sheen. The leaves turn brilliant red/ orange in autumn. The flowers are numerous and are produced in large fluffy plumes of purplish-pink flowers (these look like a haze of smoke, hence the common name). They are 15 – 30 centimeters long with each flower 5 – 10 millimeters in diameter with 5 pale yellow petals. Eventually most of the flowers in each inflorescenes abort, elongating into yellowish pink to pinkish purple feathery plumes. The flowers are either male or female. The fruit is drupaceous that is about 2 – 3 millimeters in size with a fleshy outer coating.

Cotinus coggygria ’Royal Purple’ is commonly known as the Smoke Tree or Smoke Bush. Cotinus coggygria is native to southern Europe, east across to central Asia and the Himalaya to northern China. It is commonly grown as an ornamental plant with several cultivars available. This plant has been cultivated in Britain since 1656. For more than three centuries it was known as Rhus cotinus, a name that is occasionally still in use. It should be planted in full sun in order to achieve optimum color.

The etymological root of the binomial name Cotinus is derived from the ancient Greek  kotinus, ’Wild Olive’. Coggygria is derived from the ancient Greek name for the ‘Smoke Tree’.

Cotinus coggygria 'Royal Purple' (12/11/2011, Kew, London)

The landscape architect may find Cotinus coggygria ’Royal Purple’ useful as a large, purple ornamental deciduous shrub which produces a flowering mass in summer and has bright autumn colours. It can form a dark dramatic back drop for other planting.

C. coggygria ’Royal Purple’ has been awarded the prestigious Royal Horticultural Societies annual Award of Garden Merit in 1993.

C. coggygria ’Royal Purple’  prefers a moderately-fertile, moist, well-drained soil. It will tolerate most pH of soil.

Maintenance: This plant requires little maintenance. If necessary it may be pruned hard in March.