swamp white oak (Quercus bicolor)
First place champion swamp white oak in Boulder at Green Mountain Cemetery.
Species info:
Leaves: Simple, alternate, 4–7 inches long and 2–4½ inches wide; margins with large, irregular blunt teeth; upper surface dark green, underside pale whitish and fuzzy (hence “bicolor”)
Leaflets: N/A (simple leaves)
Leaf Surface: Glossy dark green above; velvety white beneath
Bark: Light brown to gray, flaky or scaly; twigs similarly flaky or scaly and hairless
Flowers: Male flowers are yellow-green catkins 2–4 inches long; female flowers small, green to red, appearing in mid-spring with the leaves
Fruit: Acorns ½–¾ inch long, single or paired on a stalk 1–4 inches long; tan with a slightly fringed cap covering about one-third of the nut
Botanical: Quercus bicolor
Family: Fagaceae
Mature Height: 50–60 feet (some larger in optimal conditions)
Canopy Spread: 40–50 feet; broad-rounded crown
Foliage Type: Deciduous
Tree Shape: Pyramidal in youth, rounded in maturity
Flowers: Inconspicuous; appear mid-spring with the leaves
Fruit: Edible, but requires preparation
Fall Color: Yellow-orange to brown; leaves often persist into winter
Water Use: Moderate; tolerates moist to poorly drained or compacted soils
Hardiness: Zones 3–8
Soil Preference: Prefers moist, low-lying sites but tolerant of alkaline and compacted soils
Wildlife Value: Acorns provide food for deer, squirrels, turkeys, and other wildlife
Pests/Pathogens: No major pest problems reported in Colorado
Notable Traits: Adaptable and durable oak suitable for challenging sites; bark and fuzzy leaf undersides provide year-round interest; not common in nurseries but worth planting if available
Planting recommendation: Recommended for most sites, but can develop chlorosis in some soils
Information Sources:
Michael A. Dirr, Dirr’s Encyclopedia of Trees and Shrubs. Timber Press. 2011.
Manual of Woody Landscape Plants, Michael Dirr
Trees of Utah and the Intermountain West, Michael Kuhns, Wholesale nursery catalogs
