Yellowwood is one of the rarest of native shade trees, naturally occurring in the Eastern to Central United States.  It’s most often found on the limestone cliffs of Kentucky, Tennessee and North Carolina.  However, it is hardy through Zone 4 and thus a suitable planting for southern and central Minnesota.  And, indeed, it is well worth considering as a gracious addition to your landscape.  Yellowwood grows to a height of from 30 to 50 feet with a broad rounded crown and a smooth bark.  The name yellowwood comes from its yellow heartwood, used in small amounts for specialist furniture and decorative woodturning.  

Although it is of great value as a shade tree, one of its most spectacular features is its flowering.  In late May to early June, Yellowwood produces long, white clumps of wisteria-like flowers some 6 to 12 inches long.  Flowering intensity varies from year to year with a profuse output every second to third year.  In the fall, the leaves turn a mix of yellow, gold and orange.  Quite a show!  As you might expect, the nativar is a good source for pollinators, attracting a variety of butterflies and bees.

In siting a Cladrastis kentuckea, do remember that it is a full-sized tree and should be spaced appropriately.  It does best in full sun, in well-drained soil.  It is quite tolerant of both acidic and alkaline soils.  You might want to mulch heavily over winter for the first couple of years, as it is establishing itself in our bracing Minnesota climate.  It looks great on a naturalized border.  That’s something to consider if you have some woodland.  Also, it is surprisingly tolerant of urban settings, although I’m not sure if it would be a candidate for your “hell strip” (what landscapers call the area between the sidewalk and street).  

Several cultivars of Yellowwood have been developed.  “Perkins Pink” is a nice one with, as the name implies, pink rather than white flowers.  A diminutive sister is “Kentucky Yellowwood”.  This is a medium-sized tree suitable for ornamental gardens.  It does, however, have the tendency to divide its trunk near the ground.  This tendency seems to be widespread among the various Yellowwood strains.  This bothers some folks although I think it imparts a distinctive character to the tree.

 So, if you are looking for a luxuriant, summer shade tree that puts on a show each spring and fall, consider Yellowwood.

Photo Credits:  University of Minnesota (1,2)