Feature Tree – April 2004

American Yellowwood 

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American Yellowwood

Cladrastis kentuckea (lutea)

Family: Fabaceae

Habit: Slow to medium growth, usually a low branching tree with an open, wide spreading form. Average height in Colorado is around 30’, can reach 40 to 50’ in other areas. Native from North Carolina, Kentucky, Tennessee.  Tolerates high ph soils as well as acid situations, native on limestone cliffs and ridges. Introduced 1812.

Hardiness:  Zone 4 to 8

Leaves:  Alternate, odd-pinately compound, (5) 7 to 9 (11) leaflets, entire leaf 8 to 12” long, each leaflet elliptic to ovate, acute, broad cuneate bright green.

Buds:  Terminal-absent, laterals-naked, superposed, the uppermost, largest and generally alone developing, flattened, closely packed together to form a pointed, bud-like, hairy brownish “cone”, generally less than Ό” long, nearly surrounded by the leaf scar.

Stem:  Slender, more or less zigzag, smooth, bright reddish brown, often with an odor and taste resembling that of a raw pea or bean.

Bark:  Thin, gray to light brown. On older branches and trunks will become smooth, gray and beech-like in appearance and texture. Called Yellowwood because of the heartwood is yellowish.

Flowers: Spectacular drooping panicles of white, fragrant flowers that clusters to 12” long, covering the tree in early May. Bees will frequent the tree when in bloom for the nectar.

Fruit: Pod, 3” long, flat seed pods.

Landscape Value:  Excellent tree for flowers and foliage. Medium in size with an open, spreading habit, making it a great choice for small areas and properties. Needs to be pruned in summer, will bleed profusely if pruned in winter or spring; often develops bad crotches which can split or crack in storms; supposedly can fix atmospheric nitrogen. Has been used to produce yellow dye and fine cabinet wood in the pioneer days. Full sun to partial shade.

Insect and Diseases: No serious insect pest or diseases.

Sources:  Trees for American Gardens, Donald Wyman. Manual of Woody Landscape Plants, Michael Dirr.  Fort Collins Nursery