Swamp White Oak
Photo from Matt Whitaker
Scientific Description: Swamp White Oak – Quercus bicolor – is a deciduous, medium-tall tree from the Beech (Fagaceae) family found mainly in the northeastern United States. However, we humans have translocated it throughout much of North America where Hardiness Zones are between 4 and 8. The Swamp White Oak requires low maintenance and acid soil. The Swamp White Oak achieves a height of 50 to 60 feet (occasionally taller), has insignificant male catkins and female flowers, and produces the traditional acorn. The lobed (5 to 15 lobes) leaves are a shiny green above, and a silvery color below, leading to the species epithet “bicolor”.
This tree is a long-lived specimen with excellent drought resistance. It can develop a number of disease and insect problems, including cankers, leaf spot, rusts, galls, and oak lace bug and oak mites, but these are rarely issues in residential or park settings.
This species will do well as a specimen tree, a shade tree, or as street tree.
Habitat Value: This species attracts a many birds, including those that roost in the leaves and branches (many song birds), as well as those that will eat the acorns (like many of our larger birds, including ducks and wild turkeys). Many species of insects feed on this tree, including several types of beetles and the larvae and caterpillars of certain wasp and moth species. Therefore, many smaller bird species are attracted to this tree as their primary food source.
The acorns are also favored by many types of mammals, including white tail deer, squirrels, and opossums.
This species may not flower and produce acorns until it is between 20 and 30 years old.
Photo from Matt Whitaker
Landscape Value: By Matt Whitaker of WMWA Landscape Architects
Swamp White Oak falls into a few familiar categories for ecologist, horticulturist, and landscape architects. As a species that is found in the wild in low lying, moist bottomlands (no surprise given its common name), and stream banks, this species performs well in/is often used in our developed landscapes. This connection is related to the similarity of wetter soils and developed soils, where both types of soils tend to have low oxygen conditions. The wet areas because of frequent inundation with water and developed soils because of soil compaction. Since many residential yards have compact soils, this is an excellent tree for most.
As an oak, this tree falls into another category as the number one Genus for supporting Lepidoptera (butterflies and moth) and is critical to supporting declining species in that Genus, not to mention many bird species that depend on Lepidoptera for their food. One final category/requirement is acidic soils like so many of our native plants. If you place it in or near a lawn that has had lime applied for years, be prepared to add soil acidifier to bring the pH back down. This is especially true for hollies, azaleas, blueberries, and Rhododendrons, to name a few. Most people over apply lime to lawns and should stop applying it after a few years unless you get a soil test.
Oaks are later succession tree species and can tolerate shade or full sun. They can also tolerate a range of soil moisture levels once established. Finally, Swamp White Oaks make beautiful specimen trees for their shade, dark green leaves with velvety undersides, and yellow to red fall color.
