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Publication #ENH-700

Quercus austrina: Bluff Oak1

Edward F. Gilman and Dennis G. Watson2

Introduction

This North American native oak reaches 30 to 80 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. 

Middle-aged Quercus austrina: bluff oak


Credit:

Ed Gilman, UF/IFAS


[Click thumbnail to enlarge.]

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 (Fig. 2)
Origin: native to North America
Invasive potential: little invasive potential
Uses: reclamation; street without sidewalk; shade; specimen; parking lot island > 200 sq ft; tree lawn > 6 ft wide; highway median
Availability: not native to North America

Figure 2. 

Range


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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 (Fig. 3)
Leaf type: simple
Leaf margin: lobed, entire
Leaf shape: obovate
Leaf venation: pinnate
Leaf type and persistence: deciduous
Leaf blade length: 2 to 4 inches, 4 to 8 inches
Leaf color: green
Fall color: copper, yellow, orange
Fall characteristic: showy

Figure 3. 

Foliage


[Click thumbnail to enlarge.]

Flower

Flower color: brown
Flower characteristics: not showy

Fruit

Fruit shape: round, oval
Fruit length: .5 to 1 inch
Fruit covering: dry or hard
Fruit color: brown
Fruit characteristics: attracts squirrels/mammals; not showy; fruit/leaves a litter problem

Trunk and Branches

Trunk/bark/branches: branches don't droop; showy; typically one trunk; thorns
Pruning requirement: little required
Breakage: resistant
Current year twig color: green, brown
Current year twig thickness: medium
Wood specific gravity: unknown

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.

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. Reviewed February 2014. Visit the EDIS website at http://edis.ifas.ufl.edu.

2.

Edward F. Gilman, professor, Environmental Horticulture Department; and Dennis G. Watson, former associate professor, Agricultural Engineering Department, UF/IFAS Extension, Gainesville, FL 32611.


The Institute of Food and Agricultural Sciences (IFAS) is an Equal Opportunity Institution authorized to provide research, educational information and other services only to individuals and institutions that function with non-discrimination with respect to race, creed, color, religion, age, disability, sex, sexual orientation, marital status, national origin, political opinions or affiliations. For more information on obtaining other UF/IFAS Extension publications, contact your county's UF/IFAS Extension office.

U.S. Department of Agriculture, UF/IFAS Extension Service, University of Florida, IFAS, Florida A & M University Cooperative Extension Program, and Boards of County Commissioners Cooperating. Nick T. Place, dean for UF/IFAS Extension.