Photo: Mike Masiuk
Yellowwood is native from southeastern Illinois south to Oklahoma and Mississippi, and east to North Carolina. Even in its native range, yellowwood is not a common species. It is generally found on well-drained limestone soils in river valleys and on slopes along streams. Yellowwood is hardy in USDA Zones 4-8.
It grows 30-50 feet tall with a slightly greater spread, making it quite suitable for smaller properties. Yellowwood typically has a broad, rounded crown and starts branching low on the trunk, often within six feet of the ground. It has an upright branching habit that makes for tight branch angles, so one liability is its susceptibility to breaking under heavy loads of snow and/or ice. Other than that, yellowwood is problem-free.
The alternate, pinnately compound leaves are bright green, which makes this tree stand out against others in the landscape. Individual leaflets are elliptic to ovate, and the terminal leaflet is the largest. Another good identification feature is that the base of the petiole is swollen and encloses the bud. The leaves ripen to a soft butter-yellow in fall.
Yellowwood blooms in late May or early June with fragrant, 8-14-inch terminal panicles of white, pea-like flowers. It flowers heavily in alternate years or every third year, cloaking the tree from top to bottom with those wisteria-like blooms. The flowers give way to flattened brown pods that are characteristic of members of the pea family, Fabaceae.
Yellowwood provides four seasons of interest because its smooth, light gray bark is attractive in winter, similar to that of beech trees. The heartwood is yellow, and has been used to make dyes, as well as giving this tree its common name.
Yellowwood grows best in full sun and evenly moist, well-drained soil. It is not fussy about pH, growing in alkaline and acidic situations without complaint. Use yellowwood as a specimen, lawn tree or plant in groups on larger properties.