The American Yellowwood (Cladrastis kentuckea) is native in the Southeastern States, but is hardy as a shade tree in Minnesota in our zone USDA 4b. It is a small tree, usually not exceeding 30 to 40 feet, with a short trunk and several ascending or slightly spreading branches that form a broad, rounded crown. The bark of the trunk is light gray or brown, usually smooth and attractive. The leaves are composed of seven to nine leaflets, pale green to slightly bluish, smooth and firm, each leaflet 3 or 4 inches long. The leaves turn bright yellow to gold in the autumn before they fall. In June, after the leaves have developed, the fragrant white flowers appear in loosely branched, drooping clusters, 10 to 16 inches long. The flowers are reminiscent of Wisteria flowers. In late August or early September, the flattened fruit pods mature from green to brown and are 3 to 4 inches long.
American yellowwood is an elegant tree, valued for its late flowering and for its autumn foliage. It is a nice tree for the rear corner of a residential backyard landscape. The smooth gray bark and zigzagging branches, which create a light, airy form, give it good winter interest. Young trees should be protected from sunscald in the winter by wrapping the major branches and trunk. The tree prefers full sun, and rich, moist, well-drained soil, although it is drought tolerant once established. Yellowwood is named after the rich yellow color of the heartwood.