American yellowwood (Cladrastis kentukea)
First place champion American yellowwood in Denver at South High School.
Species info:
Leaves: Alternate, pinnately compound; 8–12 inches long with 7–9 leaflets. Leaflets elliptic to ovate, 2–4 inches long; bright green in summer, turning yellow/gold/orange in fall.
Leaflets: 7–9 per leaf; terminal leaflet largest.
Leaf Surface: Smooth, thin-textured, bright green; underside similar but slightly lighter.
Bark: Thin, smooth, gray to light brown; resembles American beech bark; remains smooth into old age.
Twigs: Slender, somewhat zigzag; smooth, bright reddish-brown, often with a bluish bloom; twigs have raw pea or bean scent/taste.
Flowers: White, pea-like, fragrant; individual flowers ~1 inch; arranged in pendulous clusters (racemes) 10–16 inches long; bloom in June; very showy.
Fruit: Flattened, 2.5–4 inch long pods; gray-green turning brown by October; contain 4–6 hard-coated seeds; pods often persist through winter.
Botanical: Cladrastis kentukea
Family: Fabaceae
Mature Height: 30–40 feet
Canopy Spread: 40–50 feet; broad and rounded crown
Foliage Type: Deciduous
Tree Shape: Broad, rounded form with upright-spreading branches; typically a short trunk with major limbs beginning low (within 6 feet)
Growth Rate: Moderate
Flower: Showy
Fruit: Pods that can be messy
Fall Color: Yellow to gold or orange
Water Use: Moderate; prefers moist, fertile, well-drained soils
Hardiness: Zones 4–8
Soil Preference: Moist, fertile, well-drained soils; tolerates both high pH and acidic conditions; native to limestone cliffs and ridges
Sun Exposure: Full sun; protect from harsh winter sun and wind
Wildlife Value: Flowers attract bees for nectar; fruit pods are not typically eaten by wildlife
Pests/Pathogens: Generally few problems; occasional Verticillium wilt has been reported
Planting Recommendations: Recommended for most sites, but should be planted in protected areas and wrapped in the winter to prevent sunscald.
Information Sources:
Front Range Tree Recommendation List
Michael Dirr, Manual of Woody Landscape Plants
Michael Kuhns, Trees of Utah and the Intermountain West
