White Oak (Quercus alba), native to the entire eastern half of the United States, is found throughout all of Ohio, in habitats ranging from dry forests and fields to mesic woodlands and down slopes. Like many members of the White Oak group, the undersides of its leaves are white-green, and its wood is a light-colored beige that is almost white when freshly cut; hence its common name.
It is the most important timber tree of the White Oak group and in fact one of the most important hardwoods, with its hard, heavy, tough wood used as lumber for beams, railroad ties, flooring, barrels, furniture, and many other uses.
Its canopy is more spreading that most other trees in closely-packed mature forests or in open fields, and its fall color is often reddish-brown to reddish-purple, one of the best Oaks in this regard. White Oak acorns are relatively large and often borne in great abundance. It may reach 80 feet tall by 100 feet wide at maturity, when found in the open. As the flagship member of the White Oak group and as a member of the Beech Family, it is related to the Beeches, Chestnuts, and other Oaks.
Planting Requirements
White Oak prefers rich, deep, moist, well-drained, acidic soils, but adapts well to dry and average soils that are neutral to slightly alkaline in pH. It thrives in full sun to partial sun but is shade tolerant in youth and is found in zones 4 to 9.
Potential Problems
White Oak is generally a healthy and long-lived oak, with regular but minor cosmetic damage to its leaves and twigs due to chewing insects and pathogens.
Identifying Features
Leaf
White Oak has leaves that are alternate and slightly obovate, with the widest portion of the leaf blade being where the longest lobes are located, just above the middle. Leaf shape is highly variable in White Oak, but consists of about seven to nine finger-like rounded lobes, with some lobes being sparsely crenate.
Lobes differ greatly in their width and length, or looking at it another way, the intervening sinuses differ in the width and depth of the "space" that they create between the lobes. Lobes are not bristle-tipped, a chief characteristic of the White Oak group. Along with Swamp White Oak, White Oak has the best autumn color of members of the White Oak group, usually with crimson-brown shades of fall color.
Flower/Fruit
White Oak is monoecious, having pendulous pollen-bearing catkins in mid-spring that fertilize the miniature female flowers on the same tree. Its fruits (acorns) only take a single season to develop, a prime characteristic of the White Oak group. They fill out during the summer and ripen in early to mid-autumn, often with heavy fruit crops.
Twig
The terminal buds of White Oak are relatively large.
Although its twigs are not corky, and its branchlets are not flaky, the branches develop distinct but not unique flares of bark, especially on the undersides of horizontal branches.
In this case, the platy bark is flared on its long sides, rather than loose at the ends, as in Shagbark Hickory.
Bark
Mature bark becomes more highly ridged and deeply furrowed, but retains the light gray color that is characteristic of the White Oak group.
The growth habit of an aged White Oak may be the most majestic of any Oak. Admirers of the rugged and bold-textured Bur Oak, or of the southern Live Oak draped in Spanish Moss, may disagree. The wide-spreading growth habit of a mature White Oak, with its heavy horizontal limbs draped in layers of bark in winter, catkins in spring, acorns in summer, and reddish fall color in autumn, is a sight to behold.