10 SPRING 2015 n ARBOR AGE www.arborage.com
TREE OF THE YEAR
The Society of Municipal Arborists presents
The 2015 Urban Tree of the Year:
Yellowwood
The Society of Municipal Arborists (SMA) SMA, comprised of
urban forestry professionals worldwide, has chosen yellowwood
(Cladrastis kentukea) as its 2015 Urban Tree of the Year.
The yearly selection must be adaptable to some harsh growing
conditions and have strong ornamental traits. It is often a species or
cultivar considered underutilized by urban foresters. The Tree of the
Year program has been running for 19 years, and recent honorees
include 'Vanessa' parrotia (2014), live oak (2013), Accolade elm
(2012), and goldenraintree (2011).
Columbia, Missouri Natural Resources Supervisor Brett
O'Brien said, "Remarkably adaptable to our state's weather and site
conditions, yellowwood is a tree which is not particularly rare, but
in my opinion is certainly not planted in our area nearly enough.
It could be that it is not popularized because in un-irrigated turf
areas it's apt to be a little slow; in my experience I have found that
in landscape beds or irrigated areas it grows fairly quickly."
Indeed, the consensus is that yellowwood does well in a variety
of urban conditions so long as it gets adequate water. It's best used
in parks, wide tree lawns, or, with pruning, in narrow tree lawns.
Yellowwood is hardy in Zones 4a to 8b and is native to eastern
North America. It is a medium-maturing tree in the legume family
that matures at 30 to 50 feet tall and 40 to 55 feet wide. It can
handle high soil pH (up to 8.2) and is considered relatively pest free.
According to Cornell's Urban Horticulture Institute, yellowwood is
easy to transplant B&B or under 2-inch caliper bare root.
This tree has elegant year-round beauty. O'Brien admires the
"pendulous fragrant white fl owers, reminiscent of wisteria" and
"the smooth, elephant-grey to light brown bark of the tree's trunk,
as well as the lustrous reddish-brown stems." He said that a favorite
yellowwood of his is located in downtown Columbia on the west
side of a red brick building, in an unforgiving site where the tree
spends the early morning in deep shade and late afternoon in
blazing sunlight. Nevertheless, the yellowwood has thrived.
"Yellowwood trees admittedly have a maddening branching
habit, generally doing fi ne until the tree is about chest height,
when multiple leaders and included bark become quite common,"
PHOTO BY MICHELLE SUTTON PHOTO BY BRETT O'BRIEN
