We’ve been talking about smaller understory native trees over the winter, and the American Smoketree (Cotinus obovatus) is a stunning conclusion to our little survey.  This gorgeous small tree is sometimes called Chittamwood but by any name, it is native to the prairie covered limestone hillsides of southeastern Texas, extending up into the Ozarks, as well as the Smoky Mountains of eastern Tennessee and down into Alabama.  It is a member of the Anacardaceae family, making it a cousin to the cashews and sumacs.  In spite of its Southern roots, it is fully cold hardy through USDA zone 4.  So, it should be a good bet for central and southern Minnesota as well as the Red River Valley.  Sheltered areas up the near North Shore would also be suitable.  

You should look for well-drained soil and full sun (6 to 8 hours of direct light) when selecting a spot.  It will tolerate partial sun (4 to 6 hours) but may grumble a bit.  It will grow pretty easily and quickly from seed and transplants easily as it has a shallow, fibrous root system.  That makes growing Smoketree from seed a good winter project if you are aiming for a grove of them!

Smoketree really is a landscaping asset if you have a hot, west-facing area on your lot.  It grows well on exposed limestone and gravelly sites.  So, if you have one of these difficult areas, by all means give Smoketree a go.  Water well the first year or two and it will be happy thereafter.  It seems to be remarkably free of disease or pest problems and once established requires little care.  It usually attains a height of 20 to 30 feet with a width of 10 to 20 feet when mature.

This beauty produces silky clusters of flowers in the spring that develop into feathery seeds.  The seeds look like small clouds of smoke hovering over the leaves in the late spring and summer, giving Cotinus obovatus its common name.  These leaves are rounded (obovate), 2 to 5 inches and of a greenish blue, almost steely color.  In fall they turn a brilliant yellow to orange to fiery red.  It’s quite a show.  The bark is grayish brown and will break into scaly plates as the tree ages.  That in itself is a point of interest after leaf fall.

There are a couple of common cultivars in the trade although they may be difficult to locate.  The first is Cotton Candy™ American Smoketree Cotinus obovatus “NorthStar”.  As the name implies it is hardy to zone 3.  The other is Grace Smoketree (Cotinus ‘Grace’).  This is a hybrid of Cotinus obovatus and Cotinus coggygria.  The latter is a Eurasian species which introduces some pest problems.  You may encounter leaf spot, rust and verticillium wilt.  Die back in severe winters can be a problem.   It boasts large pink flowers in the spring and can be pruned either as a small tree or large shrub of some 15 to 20 feet.  So, if you want to try one of these fancy hybrids, you may sacrifice hardiness for showiness.  I think though, that sticking with the true native Cotinus obovatus will provide ample rewards over many disease-free years.

Photo Credit: University of North Carolina (1), North Carolina State University (2)