UT Gardens’ November 2018 Plant of the Month: Smoketree
Submitted by James Newburn, jnewburn@utk.edu
Assistant director and curator of the UT Gardens, Knoxville

Fall gives us a chance to examine landscape plants that provide more than one season of interest. I have been struck with the beautiful fall color that Cotinus coggygria ‘Velvet Cloak’ exhibits. Commonly called smoketree or smokebush, Cotinus is typically grown as a multistemmed shrub, though it is sometimes seen in a tree form.

The beautiful fall color of Cotinus coggygria 'Velvet Cloak' and its pink panicles in early spring and summer are among the reasons this shrub is a popular specimen plant for any landscape. Photo by J. Newburn of a specimen in the UT Gardens, Knoxville.

The value of this species in late spring or early summer is the fantastic, delicate pubescent (hairy) pink panicles (the structure that holds the insignificant flowers), that emerge and give a cloud of “blooms” above the foliage. Commercially, several purple-leaved cultivars are available that are very popular as well as green-leaved selections. Velvet Cloak is stunning with the pink blooms above the dark purple foliage in spring but equally impressive with striking red, orange and russet fall foliage.

Smoketrees are best grown in full sun in well-drained soil. Standard varieties can get 10 feet to 15 feet tall with the multiple stems of the shrub becoming somewhat gangly in appearance. At UT Gardens, Knoxville, we utilize a technique called coppicing whereby we cut the stems back to a few inches above the ground in late winter or early spring to create a denser, more uniform shrub that reaches between 4- and 6-feet tall in one season. It can be utilized in the landscape as a single specimen acting as a focal point, in a mixed shrub border or in groups in large landscapes.

After their impressive blooming period usually in June, Velvet Cloak and Grace, a cross of Velvet Cloak and C. obovatus, both exhibit wonderful fall color. In hotter parts of the state the purple foliage may dull somewhat in late summer. Also, extended heat in the autumn may affect the vibrancy of fall color. This seems to be more the exception rather than the rule.

Choosing plants that have multiple season appeal is always a smart idea in designing gardens and landscapes and Velvet Cloak would certainly fall in that category. Check out the UT Gardens and other botanical gardens several times a year to garner ideas and see specimens of smoketrees and other plants that will enhance your garden throughout the year.

The UT Gardens includes plant collections located in Knoxville, Jackson and Crossville. Designated as the official botanical garden for the State of Tennessee, the collections are part of the UT Institute of Agriculture. The Gardens’ mission is to foster appreciation, education and stewardship of plants through garden displays, educational programs and research trials. The Gardens are open during all seasons and free to the public.

For more information, see the Gardens website: ag.tennessee.edu/utg​.

Published November 10, 2018