Culture
Easily grown in average, medium moisture, well-drained soils in full sun. Tolerates some dry soils once established. Best sited in a location protected from strong winds. Prune in summer because cuts made in late winter or spring tend to bleed.
Noteworthy Characteristics
Cladrastis kentukea, commonly called American yellowwood, is a medium-sized, deciduous tree of the legume family that typically grows 30-50’ tall with upright branching and a broad, rounded crown. It is noted for its pinnately compound foliage, panicles of fragrant white spring flowers, autumn seed pods and yellow fall color. The species is native to the southeastern U.S. In Missouri, it typically occurs in several southwestern counties near the White River and its tributaries. Pinnately compound leaves (usually with 7-11 leaflets) open as yellowish green, turn bright green in summer and then turn yellow in fall. Intensely fragrant, wisteria-like, white flowers in large, drooping, terminal panicles (10-15” long) will cover a mature tree in late spring. Profuse bloom may occur only once every 2 or 3 years however. New trees may not bloom for the first 8-10 years. Bloom is similar in appearance to that of black locust (Robinia). Flowers give way to flat seed pods (2.5-4” long) that mature in September-October. Species was formerly called Cladrastus lutea.
Genus name comes from the Greek klados meaning branch and thraustos meaning fragile for the brittle twigs.
Specific epithet means of Kentucky.
The wood of this tree contains a yellow dye that distinctively colors the heartwood and gives rise to the common name of yellowwood.
Problems
No serious insect or disease problems. Verticillium wilt may occur. Trees will bleed if pruned at the wrong time. Bark is susceptible to sun scald. Bloom may be damaged by late spring frosts. Yearly bloom may not occur. Branching is fragile and vulnerable to damage from winter snow/ice or high winds.
Uses
Excellent small tree for residential lawns, particularly on smaller properties. Also may be planted near patios and terraces. May be effectively grouped on larger properties. Roots go deep, so other plants may be easily grown underneath.