Buying and Growing Smoke Trees and Smoke Bushes
The other day a visitor to the garden asked me how I grew smoke bush. There are two species of Cotinus and both grow in my garden.The American Smoke Tree, C. obovatus, is a rare native ofTennessee, Alabama, Kentucky and Texas where it can grow up to 10 metres tall by near as much across. Fifteen years ago I planted a small copse of this species. The plants were watered a little for a year or two after planting but haven’t been watered since. Despite this neglect from the hose they have flourished, growing well even during the drought years. I didn’t train them to a single trunk so they are more shrub-like in shape, the best being six metres tall by 5 metres across. During summer the egg shaped leaves have a bluish cast and contrast nicely with the pinkish flower panicles. During May these trees put on an amazing autumn show as their leaves turn brilliant scarlet, pink and orange. It’s as rare in cultivation as it is in the wild. When I was looking for trees to plant I bought every single one that was available in Australia at the time, a grand total of ten. Propagation from cuttings is difficult so seed is the usual option but germination is at best spasmodic and at worst fails completely.
The European species, C. coggygria, is much more likely to be found in Australian gardens and there are now half a dozen varieties available, all worth having. I pollard an old purple leafed selection, which could be ‘Foliis Purpureus’ or ‘Notcutt’s Variety’, I’m not sure which and the names seem interchangeable in Australia. Every winter I cut this shrub down to ninety centimetres. Whilst this means I don’t get any flowers the strong vertical new growth often reaches two metres in a season. These stems grow strongly well into autumn and still produce fresh, glossy new leaves right into April.
In the late 1970s Peter Dummer, then a propagator at the famous Hillier’s Nursery in the UK, raised five seedlings from a deliberate cross he had made between C. obovatus and C. coggygria ‘Velvet Cloak’. He named one of the seedlings ‘Grace’ after his wife. My plant of ‘Grace’ has been in for a dozen years or so. It was a brute to begin with sending out long floppy wands which made it more gormless than graceful. I nearly dug it out several times. It took a lot of work over many years to train it into something resembling a tree but now it is one of the wonders of the garden. The plum coloured flower panicles are huge and the pink veined, deep plum leaves are large and handsome. ‘Grace’ is now 6 or 7 metres tall and still throws out long floppy branches but these now give the tree an air of elegance. The autumn leaves are stunning turning red, scarlet, pink and butter.
At the other end of the scale from the tree like ‘Grace’ is Cotinus coggygria ‘Young Lady’ which has been growing for a few years in our New Mediterranean Garden. Naturally a dwarf shrub it has flower panicles at the tip of every growth and even the current seasons new wood. Whilst this makes it difficult to find good cutting material it makes it one of the joys. From all accounts it will grow up to 2 metres tall by a little less across although ours is still only 130cm tall. The flower panicles are green at first but soon turn dusky pink. All Cotinus are drought tolerant and frost hardy and to my knowledge have no known problems although they need protection from rabbits and hares when they are young.