What Is the Difference Between a Purple Smoke Bush & a Purple Smoke Tree?

The smoky filaments are the remnants of the sterile flowers.

Although the two plants may have drastically different forms, purple smoke tree and purple smoke bush are the same species. According to the Virginia Cooperative Extension, pruning habits train this versatile plant into a shrub or a small tree, whichever the homeowner desires.

Identification

Purple smoke tree and purple smoke bush are the same plant, Cotinus coggygria. This is a tough, deciduous shrub or small tree that has purple or green foliage. Soft clusters of thread-like panicles, or flower clusters, appear in late spring, giving the plant its common name. C. coggygria also gives a space bright fall color. It is relatively pest-free, prefers full sun and grows in most soils. Nurseries sell many varieties, including the purple-leaved Purpureus and Royal Purple cultivars and the green-leaved Daydream.

Pruning

C. coggygria sends up lanky stems or small trunks if left unshaped. However, to grow the plant as a tree, select strong leaders and prune as a multi-trunked tree. In this form, C. coggygria grows up to 15 feet tall. Prune the dormant shrub close to the ground to encourage many smaller stems if you prefer a bush form.

American Smoketree

Although related to C. coggygria, American smoketree (Cotinus obovatus) grows up to 25 feet tall and has less visible plumes than C. coggygria. It does, however, have brilliant fall color and tolerates drought. The American smoketree may be available through specialty nurseries but is much less common than its showy cousin.

References

• Virginia Cooperative Extension: Smokebush, Smoketree
• University of Connecticut Plant Database: Cotinus Coggygria
• University of Illinois Extension: Smokebush, Smoketree

Resources

• Arbor Day Foundation: Smoketree