Swamp White Oak

(Fagaceae - Beech Family)

Form

• large shade tree
• maturing at about 60' tall by 60' wide under urban conditions, but larger in the wild
• upright oval growth habit in youth, becoming very rounded to slightly spreading with age
• medium growth rate

Culture

• full sun to partial sun (partial shade tolerant in youth)
• performs best in full sun in moist to wet, deep, acidic soils, but is very adaptable to dry soils, and is somewhat adaptable to soils of alkaline pH
• propagated by seeds
• Beech Family, with no serious diseases or pests, although areas of a mature trunk having the distinct absence of bark ridges (a fasciation that can be caused by insects, fungi, or bacteria) and stem galls (oak bullet and rough bullet gall, caused by gall wasps) are occasional cosmetic blemishes
• moderately available in ball and burlap form
• member of the White Oak group; some of these members may hybridize freely in the wild, resulting in a blending of such traits as leaf shape and fall color
• Swamp White Oak is very sensitive to being transplanted in Autumn, and care should be taken to amend the soil, fertilize, water thoroughly, mulch adequately, and avoid Winter salt spray, to enhance survival chances during the first Winter, if transplanting cannot be delayed until Spring
• occasionally, moderate chlorosis of the foliage will occur in soils of alkaline pH, although Swamp White Oak is more adaptable to these conditions as compared to Pin Oak (Quercus palustris) ; treatment is usually rendered by annual fertilizer applications to the soil, including iron and other micronutrients

Foliage

• dark green, alternate, slightly obovate, with variable leaf margins that range from shallowly sinuate with either small rounded lobes or large crenate teeth, to moderately deep sinuses with prominent rounded lobes
• leaves are whitish-green underneath, resulting in a bicolor effect in the breeze (and hence the specific epithet name)
• leaves have a fairly short petiole, and the leaf blades can become chlorotic in alkaline soils, but are usually not so
• fall color is often a poor chartreuse to yellowish-brown, but occasionally reddish-purple, golden, or golden-brown in excellent years

Flowers

• yellow-brown pendulous male catkins are obvious and prominent in late April, but are ornamentally insignificant, as are the very small pistillate flowers

Fruits

• a moderate-sized acorn (1" long), maturing in a single season, with a cap covering the upper one-third of the oval nut, on a very long but thin peduncle (1" to 4" long), either single with an aborted miniature acorn on the peduncle, or in pairs

Twigs

• yellowish-brown in youth, turning to brown-gray with maturity, usually stout

Trunk

• young trunks and branches are gray-brown and shredding to lightly exfoliating, but quickly mature to overlapping long vertical scales that flare outward along one exposed side, on the upper trunk and the undersides of large limbs
• mature lower trunks are either scaly, or heavily ridged and furrowed
• the prominently flared bark of this species (and many other members of the White Oak group) contribute greatly to its overall bold texture in Winter

ID Summary

• Swamp White Oak, while having the typical overlapping scales of the White Oak group, has crenate margins on a 6" long obovate leaf, 1" long acorns on 3" long peduncles (with an occasional aborted fruit on the very thin stalks), and infrequent galls on the young stems; in addition, the upright oval growth habit of youth becomes a broad rounded crown with age, often found in its native habitat in moist to swampy areas, but adaptable in urban environments to dry soils

USAGE

Function

• shade tree for large lawns, golf courses, parks, or naturalized areas, including areas that are dry, wet, or normally dry areas that are occasionally flooded
• valuable timber tree, with its wood prized for beams, boards, railroad ties, furniture, and especially floors

Texture

• medium texture in foliage and bold texture when bare
• thick density in foliage and when bare

Assets

• wet site or dry site adaptable
• bicolored foliage becomes evident in the wind
• bold texture in Winter
• nuts attract wildlife (large birds, deer, and especially squirrels)

Liabilities

• fall color is often poor
• fruit litter with maturity
• a small amount of dead foliage may remain on the interior branches in Winter (but not much)

Habitat

• zones 3 to 8
• native to the Eastern United States

SELECTIONS

Alternates

• large rounded shade trees (Acer platanoides, Fraxinus americana, Gleditsia triacanthos, Sophora japonica, etc.)
• trees adaptable to both dry sites and wet sites (Celtis laevigata, Gleditsia triacanthos, Fraxinus pennsylvanica, Taxodium distichum, etc.)
• wildlife attraction hardwood trees (members of the genera Fagus, Carpinus, Carya, Juglans, Nyssa, Quercus, etc.)
• trees with bicolored foliage (Acer rubrum, Acer saccharinum [liability], Betula nigra, Populus alba [liability], Quercus alba, Quercus muehlenbergii, Salix alba, etc.)

Variants

• straight species is the available choice

NOTES

Translation

• Quercus is the Latin name for Oak.
• bicolor translates as "two colors", referring to the lower sides of the leaves being whitish-green and a dramatic contrast to the dark green uppersides of the leaves when the wind blows.

Purpose

• Swamp White Oak is a large shade tree that can adapt very well to either wet or dry sites.

Summary

• Quercus bicolor is known as a large, rounded shade tree noted for its bicolored foliage in the breeze, ornamental bark and bold texture in Winter, and adaptability to wet or dry sites.