Introduction

This deciduous native tree reaches 50 to 70 feet in height with an equal spread, forming a broad, open, rounded canopy and casting dense shade below. The shiny, dark green, 5- to 6-inch-long by 2- to 4-inch-wide leaves have fine white hairs on their underside, and irregular margins. In fall, the leaves turn a showy yellow/brown to red before dropping. The oval, 1-inch acorns are usually found in pairs on 1- to 4-inch-long stems, and are quite attractive to a variety of mammals and birds. Swamp white oak has deeply ridged and furrowed, dark brown bark, and forms an impressive shade tree.

General Information

Scientific name: Quercus bicolor

Pronunciation: KWERK-us BYE-kull-er

Common name(s): Swamp white oak

Family: Fagaceae

USDA hardiness zones: 4A through 8B (Fig. 2)

Origin: native to North America

Invasive potential: little invasive potential

Uses: parking lot island > 200 sq ft; street without sidewalk; tree lawn > 6 ft wide; specimen; shade

Availability: not native to North America

Description

Height: 50 to 70 feet

Spread: 50 to 70 feet

Crown uniformity: irregular

Crown shape: round, oval

Crown density: moderate

Growth rate: moderate

Texture: coarse

Foliage

Leaf arrangement: alternate (Fig. 3)

Leaf type: simple

Leaf margin: lobed, dentate, sinuate/undulate

Leaf shape: oblong, obovate

Leaf venation: pinnate

Leaf type and persistence: deciduous

Leaf blade length: 4 to 8 inches

Leaf color: green

Fall color: yellow, copper, red

Fall characteristic: showy

Flower

Flower color: brown

Flower characteristics: not showy

Fruit

Fruit shape: round, oval

Fruit length: .5 to 1 inch

Fruit covering: dry or hard

Fruit color: brown

Fruit characteristics: attracts squirrels/mammals; not showy; fruit/leaves a litter problem

Trunk and Branches

Trunk/bark/branches: branches droop; showy; typically one trunk; thorns

Pruning requirement: needed for strong structure

Breakage: resistant

Current year twig color: brown

Current year twig thickness: medium, thick

Wood specific gravity: 0.72

Culture

Light requirement: full sun, partial sun, or partial shade

Soil tolerances: clay; sand; loam; slightly alkaline; acidic; extended flooding; well-drained

Drought tolerance: moderate

Aerosol salt tolerance: moderate

Other

Roots: not a problem

Winter interest: no

Outstanding tree: yes

Ozone sensitivity: unknown

Verticillium wilt susceptibility: resistant

Pest resistance: resistant to pests/diseases

Use and Management

Found in the wild along streams and in swampy soils, swamp white oak should be grown in full sun to partial shade on acid soils, showing severe chlorosis on alkaline soils. These trees are very long-lived, surviving for more than 300 years. They tolerate soil compaction, drought and some salt exposure. They should be tried more often in urban areas. Transplanting is best done in springtime. Container-grown material can be planted anytime.

Propagation is by seed.

Pests

Borers, variable oak caterpillar, oak slug caterpillar and other caterpillars are pests although natural enemies usually keep infestations under control. Gypsy moth can cause significant damage. There are many other potential pests on oak.

Diseases

Some diseases of this oak are anthracnose, canker, powdery mildew, shoestring root rot and oak wilt. Leaf spot diseases are usually harmless. Leaf blister can cause moderate to severe defoliation. A dormant spray may reduce symptoms.