Australian tree fern

Sun

Partial shade or bright filtered light; tolerates more sun in humid coastal climates if the roots stay moist. Shelter from hot afternoon sun and drying winds.

Water

Keep the root zone consistently moist but not waterlogged. Water frequently during hot weather; container plants may need daily watering.

Soil

Humus-rich, moisture-retentive soil with good drainage, preferably slightly acidic. Avoid compacted soil and standing water.

Height

20-40 ft (6-12 m) outdoors in suitable climates; usually smaller in containers

Spread

10-15 ft (3-4.5 m)

Foliage

Evergreen. Large, bright to mid-green, finely divided fronds form an umbrella-like crown. Young fronds unfurl as hairy croziers, and older trunks develop conspicuous oval leaf scars.

Growth

Fast for a tree fern in warm, moist conditions; slow in cool climates or containers.

Care needed

Medium

• Heat tolerant
• Wildlife
• Low allergen

Northern hemisphere months. In Australia, shift them by six.

Difficulty

Hard

Toughness

Needs looking after

Pick your zone, country, light and whether you have pets.

1. Planting day

   4 ft (1.1 m)

2. After 1 year

   12 ft (3.7 m)

3. After 2 years

   21 ft (6.4 m)

4. After 3 years

   30 ft (9 m)

   full size

About 3 years to full size.

From a typical nursery size, at an average rate for this kind of plant. A rule of thumb, not a forecast.

Cats and dogs

Safe

Native to

Australia

Invasive in

the US

Growth rate

Moderate

• Water the soil deeply and regularly; do not rely on misting the trunk or foliage to supply the roots.
• Apply a dilute, balanced liquid feed monthly during active growth, following the product's container-plant rate.
• Mulch the root zone with leaf mould or compost, keeping mulch clear of the trunk base.
• Shelter the crown from frost and cold wind; move container plants into a bright, frost-free space before freezing weather.
• Plant nursery-grown specimens with an intact root system; do not buy or plant severed trunks as you might with some other tree ferns.

Pruning. Remove fully brown or broken fronds in spring or during active growth, cutting the stalk without damaging the trunk or crown. Leave green fronds in place and never cut off the growing tip.

Spring

Plant or repot once frost risk has passed, preserving the root ball and the original planting depth.

Spring

Refresh the mulch and begin dilute feeding when new fronds start expanding.

Summer

Check soil moisture frequently and water deeply, especially during hot or windy weather.

Late summer

Inspect frond undersides for scale insects and mites, particularly on plants kept under cover.

Autumn

Stop feeding as growth slows and arrange frost-free shelter for container plants in cold regions.

Winter

Keep sheltered plants slightly moist rather than wet, and remove heavy snow before it bends or breaks fronds.

• Use as a canopy plant above lower ferns and shade-loving groundcovers in a sheltered woodland garden.
• Place as a single architectural specimen in a courtyard with enough room for the mature fronds.
• Combine with broad-leaved plants such as hostas and cast-iron plants for contrasting foliage textures.
• Grow in a large movable container beside a shaded terrace where winter shelter is available.

Garden styles it suits: Modern tropical, Architectural minimal, Woodland, Tropical, Australian native and Luxury resort.

Plant it with: Bird's nest fern, Cast-iron plant, Clivia, Hosta, Japanese painted fern and Soft shield fern.

Wildlife: The crown and fibrous trunk can shelter small invertebrates, and older trunks may support mosses and other ferns in humid gardens. It produces spores rather than flowers, so it offers no nectar or pollen.

• Brown, crisp fronds usually indicate dry roots, hot sun or drying wind: restore steady watering and provide afternoon shade and shelter.
• Frost can blacken fronds and kill the growing point: protect before freezing weather rather than relying on recovery afterward.
• Scale insects and spider mites can infest sheltered plants: inspect frond undersides, wash off mites and treat persistent infestations with a product labelled for ferns.
• Root rot causes decline in persistently wet, poorly aerated soil: improve drainage, empty container saucers and avoid keeping the root ball saturated.

Not known to be toxic to people, cats, dogs or horses, although species-specific toxicity information is limited. Do not eat the fronds or croziers; the hairs and scales on young growth can irritate skin and eyes.

Where it spreads. Invasive in Hawaii and parts of New Zealand and South Africa, where windblown spores allow it to colonize moist habitats. Check local restrictions before planting, especially near native forest.

• Soft tree fern (Dicksonia antarctica)

  Usually has a much thicker, densely fibrous trunk and a slower growth rate. Australian tree fern has a slimmer trunk with conspicuous oval scars where old fronds have fallen.

• Rough tree fern (Cyathea australis)

  Usually has a rougher trunk with persistent, prickly frond bases and coarser foliage. Australian tree fern generally sheds old frond bases more cleanly, exposing oval scars.

The epithet cooperi honours Daniel Cooper, a nineteenth-century Australian politician and patron.

Propagation. Propagate from spores sown on a clean, moist medium under warm, humid conditions; raising a trunked plant takes years. It is not normally divided and will not reliably regrow from a severed trunk.

Accepted botanical name

Sphaeropteris cooperi

Native range

New South Wales and Queensland.

Sources: GBIF (CC BY 4.0) and Trefle (CC BY 4.0). The care and design notes are LandscapeGPT's own.