An Excellent Native Texas Shade Tree
One of our regions most underutilized deciduous native oaks and our latest Texas Superstar® is Quercus muehlenbergii, which is most commonly known as chinkapin oak or chinqapin oak. Other vernacular names associated with this tree such as bray oak, chestnut oak, yellow chestnut oak, rock chestnut oak, rock oak or yellow oak generally allude to the resemblance of its 4″ to 6″ long leaves to those of chestnuts or chinquapins (Castanea spp.) or alternatively to the tough rocky conditions of their native haunts. Although this member of the beech family (Fagaceae) can obtain a larger size in the eastern U.S., it usually grows to be a handsome medium size shade tree in the 30′ to 50′ tall range in many of our urban or suburban Texas landscapes. Thus, chinkapin oak remains more in scale with residential plantings than some larger shade trees.
The handsome foliage emerges reddish to green and matures to a dark lustrous green in late spring. Foliage of chinkapin oak is not frequently bothered by insect or diseases, remaining presentable throughout the growing season. In some years chinkapin oak will also develop a pleasing yellow, orange–brown, to rich brown fall color. As a young plant the canopy is typically upright and oval, with the crown eventually becoming more rounded and spreading with age. The flaky light brown to grayish mature bark is reminiscent of that of white oak (Quercus alba). Chinkapin oak’s sweet acorns are very palatable to a variety of animals, thus serving as an environmentally friendly food source for attracting urban wildlife.
Tolerance to a wide range of environmental conditions is one of the chinkapin oak’s best characteristics. Chinkapin oaks are very heat tolerant, thriving even in El Paso. Once established chinkapin oaks can also withstand considerable drought. Chlorosis (yellowing of the foliage), which is so common on many trees in high pH soils, is seldom a problem with chinkapin oak. Trees actually grow better on a neutral to somewhat alkaline soil, which is good news for many of us in Texas, but this species also tolerates acid soils. Trees exhibit tolerance to a wide range of temperatures, growing well in USDA zones 9a (the upper Texas Coastal Plain) to 5 (Central U.S. Plains to the Midwest). Growth rates are moderate on most sites. For the best adaptation in our area, growers should be encouraged to use seed collected from regional native stands. Although chinkapin oaks have been reported to contract oak wilt, they are also reported to be less susceptible than many alternative red oak or live oak species in Texas landscapes.
Prepared by Michael A. Arnold, 06/03/04