Tree of the Month
The Ohio Chapter ISA continued efforts is to advance responsible tree care practices through research, technology, and education while promoting the benefits of trees. This month Tree-Of-The-Month is commonly known as the Sawtooth Oak(Quercus acutissima).
The Sawtooth Oak is native to Japan, China, and Korea. The Sawtooth Oak is a species that was first introduced into the eastern United States around 1862. Sawtooth Oak is commonly known as a tree species that can be easily be grown and readily establishment in most Ohio landscape sites if sited properly. One of the unique special traits of the Sawtooth Oak is its clean, glossy appearance of the foliage. The foliage of the Sawtooth Oak is unblemished and glossy-green all summer long. In the fall, it turns yellow, finally aging to rich brown. Though the leaves of the Sawtooth Oak look decidedly un-oak-like, the appearance of the acorns in the fall identifies this tree with the plant Genus Quercus (Oaks). Often the leaves of Sawtooth Oak are confused with the tree commonly known as American chestnut (Castanea dentata).
The Sawtooth Oak produces heavy fruit(acorn) production at an early age, serving as an important source of food in late summer and throughout autumn for wildlife. Large birds (crows, bluejays, turkeys), squirrels, deer, raccoons, opossums, and other mammals adore the large, abundant crops of acorns, which are borne heavily every other year, if not every year. Placement of a Sawtooth Oak near sidewalks and other publicly accessible surfaces can create slip fall hazards.
The Sawtooth Oak tree is very suitable for urban planting and does well in areas were large parking lot islands (> 200 square feet in size); wide tree lawns (>6 feet wide). The Sawtooth Oak is recommended for buffer strips around parking lots or median strip plantings in the highway; shade tree; specimen; residential street tree. The Sawtooth Oak has been successfully grown in urban areas where air pollution, poor drainage, compacted soil, and/or drought are common. Sawtooth Oak is known to lift sidewalks and curbing if planted in tree lawns less than eight feet wide or too close to walks.
The Sawtooth Oak is easy to identify by its pyramidal shape in youth, striated young bark, retained winter foliage, acorns with frilled caps, and finely serrated(sawtooth-like) leaves (from which it gets its common name). The trunk and bark of Sawtooth Oak are gray-brown and deeply furrowed. It is planted throughout most of Ohio and may reach 60-70 feet tall by 60 feet wide at maturity when found in the open. The sawtooth oak is fast growing for an oak, reaching 30 feet in 15 years. As a member of the Red Oak group and the Beech Family, it is related to the Beeches, Chestnuts, and other Oaks.
Sawtooth Oak prefers moist, well-drained, acidic soils of moderate fertility but adapts well to relatively poor, dry soils of neutral or slightly alkaline pH. It thrives in full sun to partial sun (but is shade tolerant in youth) and is grown in zones 5 to 9. However, the best performance is achieved in deep,well-drained soils. Sawtooth oak seedlings do not do well in poorly drained soils or areas subject to flooding. If underwater for 24 hours in the summer, they will not survive.
Cultivars, Improved, and Selected Materials (and area of origin)
This tree species is often sold and is available from nurseries throughout the Ohio region and it transplants easily. The Sawtooth Oak cultivar named ‘Gobbler’ was released in 1986 by the Quicksand Plant Materials Center in cooperation with the Kentucky Agricultural Experiment Station, Kentucky Department of Fish & Wildlife, and the Kentucky Division of Forestry. It was selected for resistance to insects and disease, wildlife food value, and growth form compared to similar use species. Another cultivar is called “Chenii” and its known for the features of smooth leaves and smaller acorns. Additionally, botanist have reported approximately 20 subspecies of Sawtooth Oaks with varied leaf sizes and tree forms. The feature that most clearly distinguishes the subspecies are the type of young leaves that are covered with a thick, yellow pubescence that lingers for a while after spring bud break and the variances in the teeth on the leaves being curved or erect.
It is reported that in Japan the Sawtooth Oak wood is utilized to make charcoal for the braziers for the heating water for tea ceremonies.
The Sawtooth Oak is susceptible to oak wilt, a fungal disease that invades the water-conducting vessels and plugs them. As water movement is slowed, the leaves wilt and rapidly drop off the tree. The disease begins with a crinkling and paling of the leaves, followed by wilting and browning from the margins inward. Necrosis may be strongest along the veins or between them. The symptoms move down branches toward the center of the tree, and the tree may die within 1–3 months, although some diseased trees may survive up to a year. The disease may be spread by insects (primarily beetles) or pruning tools, but most of the tree loss in oak wilt centers results from transmission through root spread between adjoining trees.
Special Note: Prune oaks in the dormant season to avoid attracting beetles that may carry oak wilt
The Ohio Chapter ISA recommends working with an ISA Certified Arborist when selecting or caring for any tree in your landscape. To better guide you on the vital plant information for the Red Buds use our friendly users guide below:
Tree Selection Tips
|Plant Family||Fagaceae (Beech Family)|
|Life cycle||Perennial woody|
|Origin||Introduced from Japan, China and Korea|
|Tree form||Symmetrical canopy with a regular (or smooth) outline, and individuals have more or less identical crown forms (see reference)|
|Does it produce shade?||Yes|
|Soil||Clay; loam; sand; slightly alkaline; acidic; occasionally wet; well-drained.|
|Bloom season||April-May and inconspicuous and not Showy. Brown in color.|
|Fruit||Produces oval fruit length is 5 to 1 inch that is dry or hard and brown in color that attracts squirrels and other mammals and is showy.|
|Plant height||60-70 feet|
|Plant spread||60 feet|
|Suitable for planting under or near electric(utility) wires||No|
|Potential Concerns||No pests of major concern although the potential list is long. It is usually pest-free. Anthracnose may be a serious problem in wet weather. Infected leaves have dead areas following the midrib or larger veins. These light brown blotches may run together and, in severe cases, cause leaf drop. Trees of low vigor, repeatedly defoliated, may die. Trees defoliated several years in a row may need spraying, to allow the tree to recover.|
Written by Mark A. Webber BCMA, CPH, LTE, MArborA, OCMNT, TRAQ
Sawtooth Oak. USDA NRCS Northeast Plant Materials Program .Quercus acutissima Carruthers. USDA.2002
Plant of the Week: Sawtooth Oak. Gerald Klingaman. University of Arkansas.2002
Quercus acutissima Sawtooth Oak. Edward F. Gilman and Dennis G. Watson. US Forest Service.1994
Photograph sources Mark A. Webber 2019