Quercus austrina: Bluff Oak1

Edward F. Gilman, Dennis G. Watson, Ryan W. Klein, Andrew K. Koeser, Deborah R. Hilbert, and Drew C. McLean 2

Introduction

This North American native oak reaches 40 to 60 feet in height and makes an attractive shade tree, with handsome scaly gray bark. The green, lobed leaves are deciduous but do not change color before dropping in fall. The insignificant, green, spring flowers are followed by small acorns, less than one-inch-long. The trunk often grows straight up through the crown with little pruning, and branches are well spaced along the trunk. This is one of the oaks which is not currently available in most nurseries, but it should be. Urban tree managers will want this oak once they find out about it.

Figure 1. Full Form—Quercus austrina: bluff oak
Figure 1.  Full Form—Quercus austrina: bluff oak

General Information

Scientific name: Quercus austrina

Pronunciation: KWERK-us oss-TRY-nuh

Common name(s): Bluff oak

Family: Fagaceae

USDA hardiness zones: 8A through 9B (Figure 2)

Origin: native to Atlantic and Gulf coastal states from southern Mississippi to southeastern North Carolina

UF/IFAS Invasive Assessment Status: native

Uses: reclamation; street without sidewalk; shade; specimen; parking lot island > 200 sq ft; tree lawn > 6 ft wide; highway median

Figure 2. Range
Figure 2.  Range

Description

Height: 40 to 60 feet

Spread: 35 to 50 feet

Crown uniformity: symmetrical

Crown shape: oval, round

Crown density: open

Growth rate: moderate

Texture: medium

Foliage

Leaf arrangement: alternate

Leaf type: simple

Leaf margin: lobed, entire

Leaf shape: obovate

Leaf venation: pinnate

Leaf type and persistence: deciduous

Leaf blade length: 1 to 6 inches

Leaf color: dark green and shiny on top, paler green underneath

Fall color: copper, yellow, orange

Fall characteristic: showy

Figure 3. Leaf—Quercus austrina: bluff oak
Figure 3.  Leaf—Quercus austrina: bluff oak

Flower

Flower color: brown

Flower characteristics: not showy

Fruit

Fruit shape: round, oval; oblong

Fruit length: ½ to ¾ inch

Fruit covering: dry or hard acorn; cap has tight brown scales, is bowl-shaped, and covers the top 1/3–½ of the shiny nut

Fruit color: tan or brown

Fruit characteristics: attracts squirrels/mammals; not showy; fruit/leaves a litter problem

Fruiting: mid to late fall

Trunk and Branches

Trunk/branches: branches don't droop; showy; typically one trunk; no thorns

Bark: whitish, scaly from about 1/3 of the way up the trunk and above, and with broad ridges

Pruning requirement: little required

Breakage: resistant

Current year twig color: green, brown

Current year twig thickness: medium

Wood specific gravity: unknown

Figure 4. Bark—Quercus austrina: bluff oak
Figure 4.  Bark—Quercus austrina: bluff oak
Credit: Gitta Hasing

Culture

Light requirement: full sun

Soil tolerances: clay; sand; loam; acidic; well-drained

Drought tolerance: high

Aerosol salt tolerance: unknown

Other

Roots: not a problem

Winter interest: yes

Outstanding tree: no

Ozone sensitivity: unknown

Verticillium wilt susceptibility: resistant

Pest resistance: resistant to pests/diseases

Use and Management

It would be well suited for planting in parking lots or along streets and boulevards where there is plenty of space for crown development. A row of bluff oaks planted on 30-foot centers lining each side of a street make a wonderful site. The medium-textured leaves make this oak stand out from other oaks. Upright to horizontal branching habit make this an easy tree to prune for vehicular clearance beneath the canopy.

Bluff oak should be grown in full sun on well-drained soil, and has good drought-tolerance.

Quercus durandii var. austrina is a synonym.

Propagation is by seed.

Pest and Diseases

No pests or diseases of major concern.

Reference

Koeser, A. K., Hasing, G., Friedman, M. H., and Irving, R. B. 2015. Trees: North & Central Florida. Gainesville: University of Florida Institute of Food and Agricultural Sciences.

Footnotes

1. This document is ENH-700, one of a series of the Environmental Horticulture Department, UF/IFAS Extension. Original publication date November 1993. Revised December 2006 and December 2018. Visit the EDIS website at https://edis.ifas.ufl.edu for the currently supported version of this publication.
2. Edward F. Gilman, professor emeritus, Environmental Horticulture Department; Dennis G. Watson, former associate professor, Agricultural Engineering Department; Ryan W. Klein, graduate assistant, Environmental Horticulture Department; Andrew K. Koeser, assistant professor, Environmental Horticulture Department, UF/IFAS Gulf Coast Research and Education Center; Deborah R. Hilbert, graduate assistant, Environmental Horticulture Department, GCREC; and Drew C. McLean, biological scientist, Environmental Horticulture Department, GCREC; UF/IFAS Extension, Gainesville, FL 32611.

Publication #ENH-700

Date: 2019-04-10
Southern Trees Fact Sheets

Related Topics

Organism ID

Contacts

  • Andrew Koeser