American woody plant expert Dr. Michael Dirr remarks that yellow wood (Cladrastis kentukea) "produces one of the most spectacular shows of large flowering trees" in the springtime. The trunk and weak-wooded branches of a yellow wood tree visually resemble those of an American beech. It grows 30 to 50 feet tall and 40 to 55 feet wide at maturity, growing fuller and more impressive in neutral to alkaline soils. Enjoy this tree in USDA Hardiness Zones 4 through 8.
Yellow wood is native to the interior of the American Southeast. It is rare across its native range, usually found either in woodlands or on limestone slopes. Localized pockets of trees dot the map across southernmost Indiana, Kentucky, Tennessee and western North Carolina. The native range also extends westward across Missouri and Arkansas to easternmost Oklahoma, according to the Lady Bird Johnson Wildflower Center.
A member of the legume family, Fabaceae, the yellow wood (Cladrastis kentukea) has a botanical name synonym of Cladrastis lutea. Other common names for yellow wood include American yellow wood, virgilia and gopherwood. Some authors write the name as one word, "yellowwood."
Newly emerging leaves are fuzzy and gray-green in spring but mature to a deep yellow-green. Each compound leaf comprises seven to nine oval leaflets. In late spring to early summer, the branch tips bear hundreds of drooping clusters of white pea-shaped blossoms. They are fragrant and resemble the flowers of a wisteria vine. According to the "A-Z Encyclopedia of Garden Plants," sometimes the floral display occurs prominently only in alternating years. In autumn the foliage turns golden-yellow to brown.
Plant a yellow wood tree in a sunny location where the soil is fertile and well-draining. It tolerates all soil pH types. When grown in a woodland setting, the plant is much more upright in habit, but when provided ample room to grow it becomes a full, rounded tree great for shade. The University of Connecticut's plant database mentions that yellow wood often retains low branches that join the trunk at 6 feet above the ground. The wood is weak, and therefore the tree should be planted in a spot sheltered from winds. If pruning is needed, undertake the task either after the flowering ends or in very late autumn or early winter; otherwise, the pruning cut wounds tend to bleed excessively.
The Japanese yellow wood (Cladrastis platycarpa) bears white flowers with a distinctive yellow spot on each blossom's base. It grows 40 feet tall and 30 feet wide. Chinese yellow wood (Cladrastis sinensis) bears white flowers with blushes of pink tones and matures 70 feet tall and 20 to 30 feet wide.