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Xanthorrhoea australis

austral grass-tree

Asphodelaceae South-eastern Australia

Attracts Pollinators Drought Tolerant Container Friendly

SunFull Sun – Part Shade

WaterVery Low · drought-tolerant

HardinessZones 9–10

Overview

Xanthorrhoea australis is a slow-growing, long-lived evergreen perennial that develops a stout, blackened trunk over many decades, eventually reaching 1-2 m (3.3-6.5 ft) tall and occasionally more. A dense crown of stiff, narrow, grey-green to deep green leaves up to 1 m (3.3 ft) long radiates from the top of the trunk, with old leaves skirting the stem below. After fire or in spring, a tall flowering spear rises from the crown, with the cream flower spike alone reaching 1-2 m (3.3-6.5 ft) and packed with small nectar-rich cream flowers that draw birds, bees, and other insects. The trunk forms from accumulated leaf bases bound by resin and grows only a few centimetres each year. It occurs in heath, dry sclerophyll forest, and woodland on sandy, low-nutrient, well-drained soils. Its very slow growth means large specimens take many decades to form and are slow to replace, and transplanted plants establish poorly, often dying if their roots are disturbed.

Native Range

Native to south-eastern Australia, occurring in Victoria, Tasmania, New South Wales, and South Australia.

Suggested Uses

Used as a feature or specimen in native, low-water, and coastal gardens, and in containers for courtyards and entrances. Suited to sandy, well-drained sites and habitat plantings for nectar-feeding birds and insects. Mature trunked plants are grown as living sculptural elements.

How to Identify

Recognised by a stout, blackened trunk topped with a dense crown of stiff, narrow grey-green leaves up to 1 m (3.3 ft) long. A tall flowering spear bearing a dense cream flower spike 1-2 m (3.3-6.5 ft) long rises from the crown, mainly after fire or in spring. The resin-bound trunk built from old leaf bases and the skirt of dead leaves are characteristic of the species.

Appearance

Size & Dimensions

Height2' - 6'6"

Width/Spread3' - 5'

Colors

Flower Colors

Foliage Colors

Fall Foliage Colors

Bloom Information

Bloom Period

Spring

A tall spike densely packed with small cream flowers is produced from the centre of the crown, most reliably in spring or following fire. The nectar-rich flowers draw birds, bees, and other insects over several weeks. Woody capsules form along the spike and release hard black seeds.

Detailed Descriptions

Foliage Description

grey-green to deep green

Growing Conditions

Sun Requirements

SunFull Sun SunPartial Shade

Requires 6-9 hours of direct sunlight daily

• Full Sun: 6+ hours of direct sunlight

• Partial Shade: 3-6 hours of direct sunlight

• Full Shade: Less than 3 hours of direct sunlight

Soil Requirements

pH Range5.0 - 6.5(Acidic)

357912

Soil Types

sand rocky

Drainagewell drained

Water & Climate

Water Needs

Very Low

Frost Tolerance

hardy

Time to Maturity

20+ years

Drought Tolerance

Drought tolerant when established

Care & Maintenance

Care Guide

Grows in full sun to light shade on free-draining sandy or gravelly, low-nutrient soils with an acidic pH of about 5.0-6.5. As a fire-adapted native it is highly drought-tolerant once established and needs little supplemental water. Sharp drainage is essential, and wet or rich soils cause fatal root rot. It is sensitive to root disturbance, so digging or transplanting around established roots is poorly tolerated. It tolerates light to moderate frost. Growth is extremely slow, with the trunk adding only a few centimetres each year.

Pruning

Pruning is not required; old flower spikes and the lower skirt of dead leaves can be removed for appearance. The dead leaf skirt is sometimes left in place, as it protects the trunk. New leaves continually replace old ones from the crown.