August Shrub of the Month-Smoke bush
To be, or not to be…a shrub or a tree? Well, in the plant world, there is a lot of gray area between what makes a tree a “tree” versus a “shrub”. RHS (The Royal Horticultural Society) has the following definition: Shrub; A loose descriptive term for a woody plant which produces multiple stems, shoots, or branches from its base but does not have a distinct single trunk. That being said, MBG’s Plantfinder, and myself, have always considered smoke TREE (cotinus coggygria), as it is commonly called sometimes, a true shrub.
Other common names include chittamwood, Texas smoketree, and wild smoketree. That’s a lot of smoke.
Cotinus can get huge-up to 15’ high and wide, which might contribute to the tree status. The leaves have a very distinct rounded shape, like little ping-pong paddles. What gives us the ‘smoke’ part of the common name are the airy, pubescent pedicels that last from early summer until September. These feathery panicles follow the insignificant yellow flowers that bloom in spring but are hardly noticed.
The most common smokebush cultivars in the trade are the purple-leaf forms like ‘Royal Beauty’ and ‘Black Velvet.’ More uncommon are the brightly colored chartreuse-colored cultivars like GOLDEN SPIRIT pictured below on Mizzou’s campus.
Even more uncommon is the native, Cotinus obovatus. This green-only species is more tree-like, reaching 20-30’ high with greenish smoky plumes and excellent fall color.
Smoke bush prefers full sun for the best color and uniform shape. It tolerates a wide range of soils as long as it’s well-drained. It is a common practice to cut smoke bush to the ground once a year to produce vigorous shoots. This works best for the red-foliaged cultivars and results in better color.
PS Before the emails start to flow…the RHS definition for “tree” is: A woody perennial plant with a single main stem, generally branching at some distance from the ground and possessing a distinct, elevated crown.
What I love about this plant;
-The fun colors available
-The soft, smoky, long-lasting panicles.
-Some cultivars have excellent fall color.
-Deer and Drought resistant.
What’s not so great;
-The common practice of cutting smoke bush to the ground can be a pain. It’s not mandatory.
-Most people underestimate the mature size-give it room!
-Can get some wonky shapes and may need some pruning work to clean up dead branches and obtain a nice shape.
Comments or questions? Email Garden-Lou at gardenloustl@gmail.com
Words and photos by Jo Batzer
© Jo Batzer, garden-lou.com-2023, All rights reserved.
