PSC 2620: Woody Trees and Shrub

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Week 10

Cotinus coggygria - Smokebush

Plant Viewer

The leaf of Cotinus coggygria is almost round in form. It has a smooth margin and is arranged alternately on the stem. Image: Derek Ramsey	Smokebush is famous for its plumes of flowers and seeds that resemble smoke, thanks to the thing long petioles.
If pruned up, Smokebush can become a small tree, otherwise it will form into a large and spreading bush.

Plant Description

Cotinus coggygria, or Smokebush, is a hardy and fast growing large shrub or small multi-stemmed tree growing 10-15 feet high and wide. It is tolerant of a wide range of soils and different pH levels, but performs best in full sun in a well-drained dry location. It has a spreading and open form that is typically wider than it is high. It can become scrubby looking if left unpruned.

The leaf is an attractive squat oval leaf, often times nearly round in shape, with an entire margin. They are 1 1/2 - 3 1/2 inches long and arranged alternately on the stem. The leaf is thin, and translucent in sunlight. The bark is a dark red-brown color with noticeable lenticels. The pith of the stem is orange in color. The leaf is green in the summer and turns a mixture of oranges and reds in the fall.

In the early summer, small yellow flowers appear which are not ornamentally important. Instead, it is the long and airy pedicles that create the show. The large clusters of pedicles create what looks like small clouds of smoke on around the canopy of the bush. When early morning dew is resting on the pedicles it creates the mirage of a thousand tiny sparkling diamonds suspended above the foliage.

Landscape Use

It is best used at the back of a shrub border to provide a nice color backdrop and where the illusion of the smoke will be most efficacious. It can be used as an ornamental tree, though it will require regular pruning to keep it looking food. Also a good choice for any hot and dry areas.

Points of Interest

Leafspot and powdery mildew can be a problem, especially when the foliage is regularly sprayed with water.

Notable Cultivars

Grace
The larger leaves are a translucent purple color when young and mature to a deep green. It has a gorgeous red and orange fall color.

Royal Purple
Perhaps the most common cultivar, it has nearly circular deep purple leaves. The pedicles are a bright red color.

Golden Spirit
A yellow-leaved cultivar that has circular leaves and beautiful bright yellow new foliage. The young foliage is often tinged with red or green around the margin. The smoke effect is not as good.