IF YOU want autumn colour, it’s hard to go past smoke bush (Cotinus) “Grace”. A large (3-4 metres), deciduous shrub, “Grace” is totally frost hardy, tolerates any amount of sun and drought and colours reliably with the onset of cooler nights, holding her deep crimson, egg-shaped leaves well into May.
There are two species of Cotinus, the smoke tree (C. obovatus) from southern North America and the similar but different smoke bush (C. coggygria) from southern Europe, central Asia and western China.
The American smoke tree is extremely rare in the wild and even more so in cultivation, especially Down Under. Plantsman David Glenn of Lambley Nursery at Ascot, Victoria has a small copse of trees. They are about six metres tall (they reach up to 10m in nature), multi-stemmed, with brilliant autumn colours of scarlet and orange.
The European-Asian smoke bush is more common and several cultivars are readily available in Australia. A large shrub (to 5m) it has similar blue-green leaves to its American counterpart that turn amber, gold and purple in autumn.
The smokey name of both species refers to their flowers, which are like puffy clouds of greyish, pinkish candy floss completely covering the plants in early summer.
According to David, “Grace” is a cross between the smoke tree and a form of smoke bush called “Velvet Cloak”, produced by Peter Dummer of Britain’s famous Hillier’s Nursery in Hampshire and named after his wife. I got onto smoke bushes early in my gardening career, when I read they were ideal shrubs for a dry corner. At the time my garden consisted of little but one gigantic dry corner so I planted Cotinus “Royal Purple” with dark purple leaves that turned deeper purple in autumn and discovered it thrived on heat, drought and neglect.
I then wanted a shrub with green leaves for another spot and found an old plant of C. coggygria growing in a local churchyard. The minister’s wife, accustomed to eccentric requests from parishioners over the years, let me dig up a sucker and this grew beautifully and has lovely autumn colour, better in fact than “Royal Purple”.
'Grace' is a cross between the smoke tree and a form of smoke bush called 'Velvet Cloak', produced by Peter Dummer of Britain’s famous Hillier’s Nursery in Hampshire and named after his wife.
Both shrubs are now well over 4m and as much again across. My favourite small smoke bush is “Golden Spirit” with brilliant, limey green leaves, that has crept slowly up to 1.4m. and like all its relations, colours beautifully in autumn. All Cotinus are extremely difficult to propagate, either from seed or cuttings. Suckers are the best bet and they make wonderful hedges, kept trimmed to avoid a bare base.
My only minor smoke bush issue is that they come into leaf late. Don’t – as I did – plant one near an early flowering crab apple, as its bare branches detract greatly from the beauty of the flowering tree. Cotinus “Grace” is available from Bill Grattan’s Bay Tree Nursery, Station Street, Mount Victoria, phone 02 4787 1851. “Royal Purple” and “Golden Spirit” are available by mail order from Clematis Cottage Nursery, www.clematiscottage.com.au