Cotinus coggygria — Smoke Tree
One of the more fanciful sites in the summer garden is a smoke tree in full flower. Individual tiny blossoms in airy, filamentous panicles appear wreathed in clouds of smoke. This unusual display, combined with striking foliage, makes Cotinus a wonderful accent plant or addition to a shrub border.
Smoke trees are deciduous, leafing out mid-April in Sonoma County and dropping their leaves in mid-to-late December. The intervening eight months begin with vibrant new foliage, followed by an arresting floral display, colorful post-flowering foliage, and stunning fall color.
Trouble-free, cotinus grows in most any type of soil in full sun to part-shade. Foliage color is generally better and brighter with more sun; in hotter inland parts of the county, some afternoon shade may be helpful. It thrives on regular garden water for a year or two after planting, but requires only low water once it has become established. No insects or diseases are known to cause problems.
Despite the common name of smoke tree, cotinus naturally grows as a large shrub, reaching 15 ft. high and wide, arching to the ground if left unpruned. But because it is amenable to all kinds of sculpting, it’s possible to create a smaller shrub or a small tree.
To form a globe-like bush, every year in late winter or early spring before bud break, cut all stems to 6-12 in. above the ground. The result will be large, gorgeously colored foliage at eye level for easy viewing, but no flowers will appear as Cotinus blooms only on old wood—that is, at least a year old—which has been removed. By pruning severely every other year, the plant will still be at manageable size and flowers will bloom on unpruned branches.
To create a small tree, single or multi-stemmed, wait until the plant has been in the ground for a couple of years, then begin to limb up the shrub. Select one to three stems that will become the single or multiple trunks of your small tree and remove other lower branches. Continue to shape this way until you arrive at a satisfying tree-like shape. You may need to remove lower and interior branches that appear annually.
There are many different Cotinus cultivars available in the nurseries. ‘Grace’ has huge, maroon leaves and spectacular fall color that turns a deep salmon pink, but branches may become unwieldy or unshapely. ‘Ancot’ has chartreuse leaves that turn yellow in autumn and is sometimes sold under its patented name ‘Golden Spirit.’
The species Cotinus obovatus is more treelike with slightly bluish green leaves that turn stunning colors of orange, rust and yellow in fall. ‘Pink Champagne’ has pink flowers.