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CYATHEA australis

Image of Cyathea australis

Family

Cyatheaceae

Botanical Name

CYATHEA australis

Plant Common Name

Australian Tree Fern, Australian Treefern, Rough Treefern

General Description

Rough tree fern is a luscious, prehistoric-plant with magnificent large green fronds with an unusual tolerance of salt spray and drier soil. This native of the mountain slopes of eastern Australia and nearby Norfolk Islands loves moist friable soils and look its best with high humidity, ample rainfall and avoidance of dry winds. Large fronds are a beautiful medium green above and light green underneath. This tree fern has a comparatively thick "trunk" which is actually an above-ground rhizome from which leaves arise. One of the most entertaining events in the life of a tree fern is the emergence and unfurling of new frond croziers, or fiddleheads.

Australian tree fern can tolerate full sun in areas with cooler summers or lots of irrigation, but in hot summer garden zones, it must have shade from the most intense midday sun. In fact, partial shade under a higher shade canopy produces elegant and lush fronds with ease. If humidity is low, wetting the trunks and crown of the plant helps reduce leaf browning or slowing of new leaf emergence. Take care to avoid getting any of the hairs of the trunk or frond stems on your skin or under your shirt, as they can lead to an unpleasant rash or at least an annoying and persistent need for itching.

The rough tree fern is well-known and utilized in Australia because of its beauty and better cold hardiness, adaptability to a wider range of soil types, and tolerance of salt spray and drier conditions. This helps differentiate it from the more globally-recognized and used Cooper's tree fern.

Characteristics

  • AHS Heat Zone

    12 - 7

  • USDA Hardiness Zone

    10 - 11

  • Sunset Zone

    H1, H2, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24

  • Plant Type

    Fern

  • Sun Exposure

    Full Sun, Partial Sun, Partial Shade, Full Shade

  • Height

    15'-30' / 4.6m - 9.1m

  • Width

    10'-25' / 3.0m - 7.6m

  • Native To

    Australia

Growing Conditions

  • Soil pH

    Acidic, Neutral, Alkaline

  • Soil Drainage

    Average

  • Soil type

    Clay, Loam, Sand

  • Tolerances

    Wet Site, Salt

  • Growth Rate

    Slow

  • Water Requirements

    Average Water, Ample Water

  • Habit

    Upright/Erect

  • Seasonal Interest

    Spring, Summer, Fall, Winter

Ornamental Features

  • Flower Interest

    None

  • Foliage Color (Spring)

    Light Green, Dark Green

  • Foliage Color (Summer)

    Light Green, Dark Green

  • Foliage Color (Fall)

    Light Green, Dark Green

  • Foliage Color (Winter)

    Light Green, Dark Green

  • Fragrant Flowers

    No

  • Fragrant Fruit

    No

  • Fragrant Foliage

    No

  • Bark or Stem Fragrant

    No

  • Repeat Bloomer

    No

  • Showy Fruit

    No

  • Edible Fruit

    No

  • Showy Foliage

    Yes

  • Foliage Texture

    Bold

  • Foliage Sheen

    Matte

  • Evergreen

    Yes

  • Showy Bark

    No

Special Characteristics

  • Usage

    Container, Feature Plant, Tropical

  • Sharp or Has Thorns

    No

  • Invasive

    No

  • Self-Sowing

    No