October / 2001
At Home in the Garden

The unusual smoketree
by:  

Sometimes plants become popular because they are simply different. With the more unusual colored foliages, a little goes a long way.
For beautiful red, maroon, or purple foliage, you may be familiar with the smoketree, or what is sometimes called the smokebush. There are two varieties commonly available today, common smoketree (or smokebush), Cotinus coggygria, and American smoketree, Cotinus obovatus. While the two are certainly similar they are not interchangeable and require different spaces in the garden to look their best.

Smoketree cultivars
Cultivars of the common smoketree are the most well-known by gardeners and can easily be found in the nurseries. The unusual flower and leaf colors make it both beautiful and intriguing. I think it is most attractive when used as a small grouping. Used singly this shrubby plant gets lost and looks a little out of place.
The simple oval leaves of the common species are bluish-green, while the leaves of the widely available cultivar Velvet Cloak are dark purple with a fall color that is reddish-purple. Royal Purple leaves are a deep maroon, almost black, with a fall color that is reddish-purple. Their unusual leaf color can certainly turn heads but they have an even more unusual flower show.
Each individual flower is yellow and only 1/8-inch in diameter. It is the hairs that come from the flower stalk on the 6- to 8-inch-long panicles that provide the real show. These hairs have colors similar to those of the foliage and can go through several color changes as the flower panicle ages. The abundance and softness of these hairs give the smoketree its name, and they do look like pillows of smoke. Flowering season is late July and August in our area.

Growing habits
While the common smoketree is more of a shrubby plant growing 10 to 15 feet tall and equally wide, the American smoketree is a little more upright, with a tree form growing 20 to 25 feet tall. The leaves are more rounded than on common smoketree, and are a wonderful dark bluish-green with a consistent and spectacular fall color of yellow, orange, and red. Plant propagators have been working on selecting cultivars of the American smoketree that will exhibit a single specific fall color. I look forward to the opportunity to use such a great plant and choose one with the fall color that is the most suitable for my design.
The American smoketree can be used as a single specimen, accent plant, or focal point in the garden; while it lacks the royal-colored foliage that many common smoketree cultivars have, it is equally beautiful with or without flowers in any garden. Full sun is preferred but I have seen smoketree growing in partial shade quite successfully. This plant is adaptable to even the toughest site but, as with any newly planted tree or shrub, they need extra care and watering until they become fully established.
As I look at my garden now I can see that it is different and I like it that way. Each year I see plants that were once considered unusual or different becoming widely available to all gardeners throughout Kentucky. How exciting this is. As gardeners we can never stop asking our garden centers and nurseries to find new plants and carry more variety each year.