Quercus phellos

Latin name: Quercus phellos
Texture: Smooth-edged, narrow leaves and dark, irregularly furrowed trunk
Common name: Willow Oak
Growth rate: Rapid, grows 25 ft. in 12 yrs
Flowers: Yellow blooms in March-May; unisexual catkin and monoecious
Fruit or cones: Rounded acorn cups (1/2” long); starts producing them at 15-20 yrs
Height & Width: Over 100 ft tall, trunk 3-6 ft wide
Light: Full sun to light shade
Moisture: High
Soil*: pH: 4.5-6.5; moist clay or loamy, slightly acidic
Type: Deciduous
Hardiness zones: 5-9
Habit: Nice balanced, rounded form; has an oval to rounded crown
Wetland indicator category**: FACW & FAC
Ecosystem benefits: Acorns are important source of food for wildlife, attracts birds and butterflies
Origin: Various regions of southeastern United States

Features:  Deciduous,rapidly growing tree¹² that is well adapted to moist, well-drained, acidic soils and full sun/light shade¹⁶. Straight trunk supports a cone-shaped crown that becomes round at maturity¹⁰. It has a fibrous root and transplants well¹³. Toxic to horses¹³.

Siting: Typically found in the woods bordering swamps, streams, or canals¹³. Commonly placed in urban settings, such as streets and parks for its shade qualities¹⁰.

Care: Plant so root flare is visible at soil surface¹⁴. At planting, water the root ball daily with two gallons of water per inch of trunk diameter for two weeks, every other day for two months and then weekly until established. Modify water recommendations to reflect site drainage and rainfall. Apply 3” of mulch over the planted area. Do not allow mulch to touch the trunk¹⁴. Needs to be planted in full sun and keep newly planted young trees healthy with regular fertilization and water during dry weather¹⁵. 

Pests: Tends to have good resistance compared to other species of oak¹³. Potential insects include lace bugs, caterpillars, and weevils¹³. Possible diseases include shoestring root rot, oak wilt, powdery mildew, and is also susceptible to wind damage¹³.

This plant does not appear on the following invasive plant lists on (2/25/24): enter date searched and check or place an X showing the site(s) below that were examined.

x USDA SC Invasive Plant Species Web site at https://www.invasivespeciesinfo.gov/  enter the plant name in the search bar in the top right of home page. If it is listed-it will usually appear as a Terrestrial Invasive. 

x SC Exotic Plant Pest Council Web site at https://www.se-eppc.org/southcarolina/

Sources:

1. Armitage, A. (2001). Armitage’s manual of annuals, biennials, and half-hardy perennials. Portland, OR: Timber Press.
2. Armitage, A. (2006). Armitage’s native plants for North American gardens. Portland, Oregon: Timber Press.
3. Armitage, A. (2008). Herbaceous perennial plants: A treatise on their identification, culture, and garden attributes.Athens, GA: University of Georgia.
4. Clemson Cooperative Extension Home and Garden Information Center.(2011). Flowers fact sheets. Retrieved from https://hgic.clemson.edu/category/flowers/
5. Clemson Cooperative Extension Home and Garden Information Center.(2011). Groundcovers & vines fact sheets.Retrieved from https://hgic.clemson.edu/category/groundcovers/
6. Clemson Cooperative Extension Home and Garden Information Center.(2011). Trees. Retrieved from https://hgic.clemson.edu/category/trees/
7. Clemson Cooperative Extension Home and Garden Information Center.(2011). Shrubs. Retrieved from https://hgic.clemson.edu/category/shrubs/
8. Dirr, M. A. (2009). Manual of woody landscape plants. Champaign, IL: Stipes Publishing.
9. Gilman, E. F. (1997). Trees for urban and suburban landscapes. Albany, NY: Delmar Publishers.
10. Lady Bird Johnson Wildflower Center University of Texas at Austin. (2012). Native plant information network. Retrieved from http://www.wildflower.org/explore/
11. McMillan, P., Plant taxonomist Clemson University, personal communication.
12. Missouri Botanical Garden Kemper Center for Home Gardening. Plant finder. Retrieved from http://www.mobot.org/gardeninghelp/plantfinder/Alpha.asp
13. North Carolina State University (2005). Plant fact sheets. Retrieved from http://www.ces.ncsu.edu/depts/hort/consumer/factsheets/index.html
14. Strother, E. V., Ham, D. L., Gilland, L. (2003) Urban tree species guide: Choosing the right tree for the right place.  Columbia, SC: South Carolina Forestry Commission.
15. University of Florida, IFAS Extension. (2011). Southern trees fact sheet. Retrieved from http://edis.ifas.ufl.edu/department_envhort-trees
16. USDA . Plant profile. (n/d).Retrieved from http://plants.usda.gov/java/
17. USDA. Plant wetland indicator status. (n/d). Retrieved from http://plants.usda.gov/wetland.html
18. Vincent, E., Environmental horticulturist Clemson University, personal communication.
19. Clemson Extension. Carolina Yards Plant Database. Retrieved from https://www.clemson.edu/extension/carolinayards/plant-database/index.html
20. Habitat Avengers Featured Native Plant: Ilex verticillata https://bugwoodcloud.org/CDN/sceppc/publications/WinterberryArticleSCNLA.pdf

*Soil pH is determined using a professional soil test. Contact your Clemson University County Extension service for assistance www.clemson.edu/extension/. Click on “local offices”.

**2012 Plant Wetland Indicator categories (quantitative derived) http://plants.usda.gov/wetinfo.html