FPS-557/FP557: Sphaeropteris cooperi: Australian Tree Fern

Introduction

The Australian tree fern is a tropical, single-trunked, giant fern that can reach a height of 15 to 30 feet. It has long, bipinnately compound, lacy leaves that give it a fine texture. The 1- to 1 ½-foot-long leaves form a handsome canopy and impart a tropical effect. The fern produces one trunk that is woolly or russet in appearance, and it may attain a diameter of 1 foot. This plant reproduces by spores found on the undersides of mature leaves.

Figure 1. Full Form—Sphaeropteris cooperi: Australian tree fern — Figure 1. Full Form—*Sphaeropteris cooperi*: Australian tree fern

General Information

Scientific name: Sphaeropteris cooperi

Pronunciation: spheer-rop-TEER-riss KOOP-per-rye

Common name(s): Australian tree fern

Family: Cyatheaceae

Plant type: tree

USDA hardiness zones: 10B through 11 (Figure 2)

Planting month for zone 10 and 11: year round

Origin: native to eastern Queensland and northern New South Wales, Australia

UF/IFAS Invasive Assessment Status: not considered a problem species at this time, may be recommended

Uses: near a deck or patio; specimen; border; suitable for growing indoor

Figure 2. Shaded area represents potential planting range.

Description

Height: 15 to 30 feet

Spread: 8 to 15 feet

Plant habit: upright

Plant density: open

Growth rate: slow

Texture: fine

Foliage

Leaf arrangement: whorled

Leaf type: odd-pinnately compound

Leaf margin: entire

Leaf shape: lanceolate

Leaf venation: none, or difficult to see

Leaf type and persistence: evergreen

Leaf blade length: 1 to 1½ feet; leaflets are < 2 inches

Leaf color: green on top, pale green underneath

Fall color: no fall color change

Fall characteristic: not showy

Figure 3. Leaf—Sphaeropteris cooperi: Australian tree fern

Figure 4. Fiddlehead—Sphaeropteris cooperi: Australian tree fern — Figure 4. Fiddlehead—*Sphaeropteris cooperi*: Australian tree fern

Flower

Flower color: no flowers

Flower characteristic: no flowers

Fruit

Fruit shape: no fruit

Fruit length: no fruit

Fruit cover: no fruit

Fruit color: no fruit

Fruit characteristic: no fruit

Trunk and Branches

Trunk/branches: no thorns; usually with one stem/trunk

Bark: brown, fibrous, with oval leaf scars in a diagonal pattern around the trunk

Current year stem/twig color: not applicable

Current year stem/twig thickness: not applicable

Figure 5. Bark—Sphaeropteris cooperi: Australian tree fern
Credit: Gritta Hasing

Culture

Light requirement: full shade

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

Drought tolerance: unknown

Soil salt tolerances: poor

Aerosol salt tolerance: poor

Plant spacing: 36 to 60 inches

Other

Roots: usually not a problem

Winter interest: no special winter interest

Outstanding plant: plant has outstanding ornamental features and could be planted more

Invasive potential: not known to be invasive

Pest resistance: long-term health usually not affected by pests

Use and Management

Australian tree fern is delightful as a specimen plant in a shaded garden. It is often planted around a shaded pool or small pond for the double image created on the water. This is a wonderful landscape plant where winter temperatures do not drop below freezing. It is sure to illicit a comment from friends and passersby.

Australian tree fern prefers fertile, well-drained, sandy loam soils. An area in the landscape that receives partial to full shade is best. This plant requires regular moisture, and it needs light fertilizing at regular intervals during the growing season.

Australian tree fern is propagated by sowing the spores found on the undersides of mature leaves.

Pests and Diseases

Australian tree fern is bothered by mites and mealy bugs, and termites may inhabit its trunk. It usually resists diseases.

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.