White Oak (Quercus alba)

American White Oak Eastern White Oak Forked-leaf White Oak Northern White Oak Oaks Quebec Oak White Oak

Quercus alba is a long-lived white oak with a broad canopy. The common name, white oak, refers to the color of its processed wood, which has a wide variety of uses – construction, for wine and whiskey barrels, making musical instruments and weapons in Japanese martial arts,… White oak is rarely cultivated as an ornamental due to its large size.

I. Appearance and Characteristics 

Quercus alba, the white oak, is one of the preeminent hardwoods of eastern and central North America. It is a long-lived oak, native to eastern and central North America and found from Minnesota, Ontario, Quebec, and southern Maine south as far as northern Florida and eastern Texas. Specimens have been documented to be over 450 years old.

Although called a white oak, it is very unusual to find an individual specimen with white bark; the usual colour is a light grey. The name comes from the colour of the finished wood. In the forest it can reach a magnificent height and in the open it develops into a massive broad-topped tree with large branches striking out at wide angles.

Quercus alba typically reaches heights of 24 to 30 metres (80–100 feet) at maturity, and its canopy can become quite massive as its lower branches are apt to extend far out laterally, parallel to the ground. Trees growing in a forest will become much taller than ones in an open area which develop to be short and massive. The Mingo Oak was the tallest known white oak at over two hundred feet with a trunk height of 44.2 m (145 ft) before it was felled in 1938. It is not unusual for a white oak tree to be as wide as it is tall, but specimens growing at high altitudes may only become small shrubs. The bark is a light ash-gray and peels somewhat from the top, bottom and/or sides.

White oak may live 200 to 300 years, with some even older specimens known. The Wye Oak in Wye Mills, Maryland was estimated to be over 450 years old when it finally fell in a thunderstorm in 2002.

Another noted white oak was the Great White Oak in Basking Ridge, New Jersey, estimated to have been over 600 years old when it died in 2016. The tree measured 8 m (25 ft) in circumference at the base and 5 m (16 ft) in circumference 1.2 m (4 ft) above the ground. The tree was 23 m (75 ft) tall, and its branches spread over 38 m (125 ft) from tip to tip. The oak, claimed to be the oldest in the United States, began showing signs of poor health in the mid-2010s. The tree was taken down in 2017.

Sexual maturity begins at around 20 years, but the tree does not produce large crops of acorns until its 50th year and the amount varies from year to year. Acorns deteriorate quickly after ripening, the germination rate being only 10% for six-month-old seeds. As the acorns are prime food for insects and other animals, all may be consumed in years of small crops, leaving none that would become new trees. The acorns are usually sessile, and grow to 15 to 25 mm (1⁄2–1 in) in length, falling in early October.

In spring, the young leaves are delicate, silvery pink, and covered with a soft blanket-like down. The petioles are short, and the clustered leaves close to the ends of the shoots are pale green and downy, resulting in the entire tree having a misty, frosty look. This condition continues for several days, passing through the opalescent changes of soft pink, silvery white, and finally, yellow green. The leaves grow to be 127 to 216 millimetres (5–8+1⁄2 inches) long and 7 to 11.5 centimetres (2+3⁄4–4+1⁄2 in) wide and have a deep glossy green upper surface. They usually turn red or brown in autumn, but depending on climate, site, and individual tree genetics, some trees are nearly always red, or even purple in autumn. Some dead leaves may remain on the tree throughout winter until very early spring. The lobes can be shallow, extending less than halfway to the midrib, or deep and somewhat branching.

Quercus alba is sometimes confused with the swamp white oak, a closely related species, and the bur oak. The white oak hybridizes freely with the bur oak, the post oak, and the chestnut oak.

Detailed description:

  • Bark: Light gray, varying to dark gray and to white; shallow, fissured and scaly. Branchlets start out as bright green, later turn reddish-green, and finally, light gray. A distinguishing feature of this tree is that a little over halfway up the trunk, the bark tends to form overlapping scales that are easily noticed and aid in identification.
  • Wood: Light brown with paler sapwood; strong, tough, heavy, fine-grained and durable. Specific gravity, 0.7470; weight of one cubic foot, 46.35 lbs; weight of one cubic meter 770 kg.
  • Winter buds: Reddish brown, obtuse, 3 mm (1⁄8 in) long.
  • Leaves: Alternate, 13–23 cm (5–9 in) long, 7.5–10 cm (3–4 in) wide. Obovate or oblong, seven to nine-lobed, usually seven-lobed with rounded lobes and rounded sinuses; lobes destitute of bristles; sinuses sometimes deep, sometimes shallow. On young trees the leaves are often repand. They come out of the bud conduplicate, are bright red above, pale below, and covered with white tomentum. The reddish hue fades in a week or less, and they become silvery greenish, white, and shiny; when mature, they are thin, bright yellow-green, shiny or dull above, pale, glaucous or smooth below; the midrib is stout and yellow, primary veins are conspicuous. In late autumn the leaves turn a deep red and drop, or on young trees, remain on the branches throughout winter. Petioles are short, stout, grooved, and flattened. Stipules are linear and caducous.
  • Flowers: Appear in May when leaves are one-third grown. Staminate flowers are borne in hairy aments 6.5 – 7.5 cm (2+1⁄2–3 in) long; the calyx is bright yellow, hairy, and six to eight-lobed with lobes shorter than the stamens; anthers are yellow. Pistillate flowers are borne on short peduncles; involucral scales are hairy and reddish; calyx lobes are acute; stigmas are bright red.
  • Acorns: Annual, sessile or stalked; nut ovoid or oblong, round at apex, light brown, shiny, 20–25 mm (3⁄4–1 in) long; cap is cup-shaped, encloses about one-fourth of the nut, tomentose on the outside, tuberculate at base, scales with short obtuse tips becoming smaller and thinner toward the rim. White Oak acorns (referring to Q. alba and all its close relatives) have no epigeal dormancy and germination begins readily without any treatment. In most cases, the oak root sprouts in the fall, with the leaves and stem appearing the next spring. The acorns take only one growing season to develop unlike the red oak group, which require two years for maturation.

II. How to Grow and Care

Sunlight

The white oak is a tree that thrives in full sun. Younger trees will tolerate some partial shade, but as the trees age, their ability to tolerate shade will become an issue. A noticeable difference will occur in trees planted in full sun. Besides tree health in full sun, you will want to ensure full sun to get the absolute best fall colors.

Temperature and Humidity

The white oak can exist in various temperatures, from a very frigid winter in Minnesota to a relatively mild Florida winter. The white oak’s optimum range has an average temperature of 55 degrees Fahrenheit. The tree thrives in USDA Zones 3-9. The white oak is more tolerant of higher temperatures than other Northern species. While other natives will likely be adversely affected by warming regional climates, the white oak will persist.

Watering

Freshly planted white oaks should be watered regularly for the first season until established. Infrequent deep soaking is the goal rather than quick daily watering. (Imagine a rainy day compared to a passing storm.) When planting the tree, mulching beneath the canopy will help it establish itself and prosper in its new location by keeping the area moist and reducing competition with grass and other plants.

Soil

White oak prefers acidic to neutral soil that is deep, moist, and well-draining.  It does not tolerate alkaline or shallow soils.

Fertilizing

White oak can survive and thrive without supplemental fertilization. But if you wish to give them extra nutrients you can add some of 12-6-6 (N-P-K) fertilizer. This has more of a ratio of nitrogen than phosphorus and potassium. Also, consider the natural environment of oaks. They grow where there is lots of forest litter. This forest litter acts as natural mulch that breaks down into organic matter and humus. So one way to give some natural nutrition is to spread mulch by your oak trees. They will love the extra organic matter.

Pruning

Branches should be pruned to avoid moist pockets or where heavy branches may fall on people or buildings. Avoid having branches that grow with leaves tight together or pressed against buildings. If rain collects in these pockets then molds and fungi can attack. White oak love having their leaves dry out in a well ventilated breeze.

To ensure that no danger occurs from the brittle hardwood branches, make sure that heavy branches do not hang over walking paths or outbuildings. Also, do not let children play near oaks in a thunderstorm as they are susceptible to falling branches and lightning strikes.

Transplanting

White oak thrives when transplanted from late spring to midsummer, owing to mild temperatures and longer daylight hours. Ensure a well-draining location, preferably in partial sunlight. Be gentle with its delicate root system for optimum success.

Pros and Cons of White Oak Trees

White oaks are amazing trees, but along with their positive characteristics they also have drawbacks. They are not for every landscape, but in the right location can be perfect.

On the positive side, white oaks are invaluable for the environment as a shelter for countless pollinators and species of wildlife while at the same time providing food for other species. Aesthetically, they make beautiful shade trees and provide an excellent focus point in a large landscape to draw the eye. They are relatively easy to care for when young and provide beautiful fall colors.

On the negative side, when the tree drops its acorns it can become messy, especially during masting years. These are years with especially high acorn yields. The tree size is not for everyone, and maintenance can get costly as you eventually need to bring in tree services for pruning. Diseases that affect oaks are on the rise in areas where the white oak is native, making the tree more susceptible to issues.

III. Uses and Benefits 

  • Cultivation

Quercus alba is cultivated as an ornamental tree somewhat infrequently due to its slow growth and ultimately huge size. It is not tolerant of urban pollution and road salt and due to its large taproot, is unsuited for a street tree or parking strips/islands.

  • Food

The acorns are much less bitter than the acorns of red oaks. They can be eaten by humans but, if bitter, may need to have the tannins leached. They are also a valuable wildlife food, notably for turkeys, wood ducks, pheasants, grackles, jays, nuthatches, thrushes, woodpeckers, rabbits, squirrels, and deer. The white oak is the only known food plant of the Bucculatrix luteella and Bucculatrix ochrisuffusa caterpillars.

The young shoots of many eastern oak species are readily eaten by deer. Dried oak leaves are also occasionally eaten by white-tailed deer in the fall or winter. Rabbits often browse twigs and can girdle stems.

  • Woodcraft

White oak has tyloses that give the wood a closed cellular structure, making it water- and rot-resistant. Because of this characteristic, white oak is used by coopers to make wine and whiskey barrels as the wood resists leaking. It has also been used in construction, shipbuilding, agricultural implements and in the interior finishing of houses. White oak splints have been used historically by Native Americans for basketry.

White oak logs feature prominent medullary rays which produce a distinctive, decorative ray and fleck pattern when the wood is quarter sawn. Quarter sawn white oak was a signature wood used in mission style oak furniture by Gustav Stickley in the Craftsman style of the Arts and Crafts movement.

White oak is used extensively in Japanese martial arts for some weapons, such as the bokken and jo. It is valued for its density, strength, resiliency and relatively low chance of splintering if broken by impact, relative to the substantially cheaper red oak.

USS Constitution is made of white oak and southern live oak, conferring additional resistance to cannon fire. Reconstructive wood replacement of white oak parts comes from a special grove of Quercus alba known as the “Constitution Grove” at Naval Surface Warfare Center Crane Division.

  • Musical instruments

Deering Banjo Company have made several 5-string banjos using white oak – including members of the Vega series, the White Lotus, and the limited edition 40th anniversary model. White Oak has a mellower timbre than more traditionally used maple, and yet still has enough power and projection to not require a metal tone ring.

Oak barrels

Barrels made of American white oak are commonly used for oak aging of wine, in which the wood is noted for imparting strong flavors. Also, by federal regulation, bourbon whiskey must be aged in charred new oak (generally understood to mean specifically American white oak) barrels.

White Oak (Quercus alba) Details

Common name American White Oak Eastern White Oak Forked-leaf White Oak Northern White Oak Oaks Quebec Oak White Oak
Botanical name Quercus alba
Plant type Native Plant
Hardiness zone 3a, 3b, 4a, 4b, 5a, 5b, 6a, 6b, 7a, 7b, 8a, 8b, 9a, 9b
Growth rate Slow
Harvest time Fall
Height 50 ft. 0 in. - 135 ft. 0 in.
Width 50 ft. 0 in. - 135 ft. 0 in.
Sunlight Full sun (6 or more hours of direct sunlight a day)
Soil condition Clay
Flower color Gold/Yellow
Leaf color Green