Quercus phellos

Willow Oak is a medium to large-size and fast-growing deciduous tree in the Fagaceae family and the red oak group. It may grow 40 to 75 feet tall and 25 to 50 feet wide and has an oval to rounded crown. It can reach up to 100 feet tall and is long-lived. In North Carolina, it can be found in all areas of the state. It has a nice balanced, rounded form and fine texture that has made it a popular shade tree for the landscape.  Willow Oak starts producing acorns at the age of 15 to 20 years. This tree is a high-value wildlife tree for birds and mammals.  It is a host plant for the larvae of the Imperial moth (Eacles imperialis), as well as numerous butterflies, including Banded hairstreak (Satyrium calanus), Edward's hairstreak (Satyrium edwardsii), Gray hairstreak (Strymon melinus), White-m hairstreak (Parrhasius malbum), Horace's duskywing (Erynnis horatius), and Juvenalis duskywing (Erynnis juvenalis).

The willow oak is native to the southeastern United States, and it is typically found in the woods bordering swamps, streams, or canals. The epithet, phellos, is the Greek name for cork. 

Willow Oak is easy to grow in acidic, average, medium to wet, well-drained soils in full sun to light shade. It is adaptable to a variety of soil types including clay soils. It is tolerant of urban pollution. It has a fibrous root system and transplants well. 

It may be utilized as a shade tree in commercial establishments, parks, golf courses, large yards, and as a street tree. It may also do well along ponds or water gardens. It is toxic to horses.

Seasons of Interest:

Bark:  Winter                Foliage: Summer and Fall             Fruits:  Fall

Quick ID Hints:

• gray to dark gray-brown furrowed bark with age
• smooth-edged, bristle-tipped, narrow, green leaves
• Leaf pubescence below in axillary tufts of hairs
• yellow-green male and female catkins appear in the spring
• rounded acorns that are up to 0.5 inches long

Insect, Diseases, and Other Plant Problems:  Most oak trees are susceptible to many diseases and insect pests: however, the willow oak tends to have good resistance. Potential insects may include scale, oak skeletonizer, leaf miner, galls, lace bugs, borers, caterpillars, and weevils.   Possible diseases include shoestring root rot, anthracnose, oak wilt, chestnut blight, cankers, leaf spots, and powdery mildew.  Chlorosis due to iron deficiency occurs on high pH soil. This tree is susceptible to wind damage.

VIDEO created by Andy Pulte for “Landscape Plant Identification, Taxonomy, and Morphology” a plant identification course offered by the Department of Plant Sciences, University of Tennessee.