Cotinus coggygria (a.k.a. The Smoke Tree) is a hardy deciduous ornamental shrub that is easy to grow anywhere in Britain. It creates one of the finest foliage displays to be found in any garden from early Spring right through to its fiery pièce de résistance during the months of September and October.
The Anacardiaceae Family
Cotinus Coggygria is part of the Anacardiacae family which comprises of approximately 870 species of flowering trees, shrubs and vines; including pistachio, cashew, mango, sumac (Rhus) and also both poison ivy and poison oak. The species are a combination of both deciduous and evergreens, most of which are to be found in the tropical and subtropical areas of the world.
Cotinus Coggygria is one of the few species in this family to thrive in a temperate climate such as Britain and was introduced into the country back in the 17th century. It is in fact native to a large swathe of the world – from Southern Europe all the way to northern China.
For over three centuries it was officially referred to as Rhus (Sumach) cotinus which is why it is still sometimes referred to as Venetian Sumac. However, Cotinus was recategorised and is now a stand alone genus with just a few species.
The Smoke Tree (Cotinus Coggygria)
It’s commonly known as the Smoke Bush or Smoketree due to the tiny delicate wispy flowers that appear like small puffs of smoke or clouds against the deep coppery purple leaves in early to mid summer.
At this time of the year the contrasting colour combination is truly arresting. It’s worth having a close look at the minute flowers and the young purple veined leaves that appear almost translucent against the sun.
As the season progresses the leaves take on a deeper intensity of colour which culminates in a firework like display of vivid reds, purples and deep oranges during the months of September and October
The multi branching shrub left unchecked can reach a height and spread, depending upon the cultivar, of up to 5 metres. However, if left unpruned, Cotinus tends to remain a rather untidy and straggly bush with little symmetry that rarely ever becomes a true tree.
Cultivation of Cotinus coggygria
As mentioned before, this hardy shrub is very low maintenance and apart from requiring full sun and well drained soil has no other specific needs.
It’s equally happy in acidic, alkaline and neutral soils and isn’t fussy about soil type growing equally well on sand, clay (well drained), chalk and loam. Despite looking rather exotic it doesn’t require a sheltered site and will even thrive in exposed areas.
Cotinus coggygria will benefit from a mulch of compost in the spring and tolerate extremely hard pruning if required.
Young plants require regular watering but once established are drought tolerant; all in all the perfect addition to any garden display. The plant, with its dramatic foliage, is equally at home in a border or as a stand alone specimen taking between 10 and 20 years to reach its ultimate height and spread.
If space is at a premium it’s still possible to enjoy the fiery Cotinus coggygria foliage when grown in a container. Obviously the size of pot will dictate how large the shrub will become before becoming pot bound. To keep a magnificent foliage display of 1-1.5m in height you will need to prune the shrub back annually during its dormant period.
Pruning can create a slight dilemma for the the gardener because a choice has to be made as to whether to have a riotous display of the small smoky puffs of flowers or create a more vivid display of larger coppery foliage. The plant needs to be pruned when it is dormant and so either in late winter or very early spring.
The smokebush flowers on the previous year’s growth and so if you want to retain the floral display just remove lengths of weak or old stems across the whole shrub but keep the main infrastructure in place.
However, if you’re prepared to sacrifice the flowers to ensure a blazing foliage display then prune back as hard as you wish. In fact, you can even coppice your shrub, but, bear in mind that Cotinus will only grow between 30-60cm vertically in any given year.
Some of the best Smoke Bush cultivars:
In recent years there have been a number of new introductions and many of these cultivars are much smaller and compact. Others have been bred for their vibrant bright yellow leaves which turn vivid shades of red and orang in the autumn.
Cotinus coggygria ‘Royal Purple’ – This is perhaps the best known of the cultivars and is the shrub that is illustrated in the photos above. Height and Spread approx. 5x5m AGM.
Cotinus coggygria ‘Golden Spirit’ – A new golden leaved variety which is much smaller and compact reaching an ultimate height of approximately 2.5 metres. AGM.
Cotinus coggygria ‘Dusky Maiden’ – This is a brand new variety with purple undulating leaves and reaches just 2 metres at maturity. Perfect for the smaller garden.
Cotinus coggygria ‘Young Lady’ – A compact dwarf cultivar that has vivid green leaves that turn a deep red in Autumn and flowers profusely. This tiny cultivar reaches its ultimate height and spread of just 1.5 metres in 5-10 years. AGM.
* AGM – stands for the RHS Award of Garden Merit.