How fast does it grow?

It is extremely slow, growing only 1 to 2 centimeters of trunk per year.

Does it need fertilizer?

It is adapted to nutrient-poor soils and generally does not require supplemental feeding.

Plant guide

Grass tree.

Xanthorrhoea preissii

Pronounced zan-thor-REE-uh PREE-see-eye

Also known as Balga

Balga — Photo by Millie Brady (CC BY) via iNaturalist

This iconic Australian native is a slow growing plant that develops a thick, blackened trunk over many years. It produces a tall, dramatic flower spike that can reach several feet in height. You will love how it adds a unique, architectural look to your garden.

Another photo of Grass tree — Photo by Rob Beattie (CC BY) via gbif

At a glance

Care level: Moderate
Plant type: Perennial shrub
Light: Full sun
Indoor light: Direct sun
Water: Every 14 to 30 days
Mature size: 3 to 5 meters
Growth rate: Slow
Hardiness: USDA 9 to 11
Bloom time: Winter to spring

Care

Ensure the soil drains exceptionally well to prevent root rot, as these plants are very sensitive to excess moisture. Watch for yellowing leaves or a soft trunk, which are clear signs of overwatering. They thrive best when left undisturbed in a sunny spot.

Watering: Water sparingly, allowing the soil to dry out completely between sessions.
Feeding: Use a low phosphorus native plant fertilizer during the growing season.
Pruning: Only remove dead, brown leaves from the base of the crown.
Repotting: These plants dislike root disturbance, so only repot when absolutely necessary.
Soil: Sandy, well draining soil
Soil pH: Acidic to neutral
Temperature: -5 to 40°C
Humidity: 20 to 60%
Drought tolerance: High
Lifespan: Perennial, can live for several hundred years.
Fragrance: Light
Deer and rabbits: High

Signs it needs repotting

Roots growing out of the drainage holes.
Water sitting on the surface for too long.
The plant appears stunted or stops growing.

Safety

People: The resin is generally considered non-toxic, but ingestion is not recommended.
Children: The stiff, needle-like leaves are sharp and pose a puncture risk to small children.
Contact allergens: The sharp, stiff leaf tips can cause mechanical skin irritation.
Airborne allergens: The pollen produced during flowering can trigger mild allergic reactions in sensitive individuals.
Edibility: The plant is not considered edible and should not be consumed.

How to identify it

Long, thin, grass like leaves
Thick, blackened, resinous trunk
Tall, cylindrical flower spikes
Dense, rounded foliage crown

Height: 1.5 to 3m
Spread: 1 to 2m
Leaves: green, blue-green, evergreen
Flowers: cream, white, 1 to 2cm
Fruit: brown, Summer

Problems to watch for

By symptom

Plant problems by symptom

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Growing it

Propagation: seed
When to plant: spring, autumn
Overwintering: The plant tolerates light frost down to about -5°C, so protect it if temperatures are expected to fall lower. Keep the soil very dry during the winter months to prevent rot.
In containers: It can be grown in large, deep pots with excellent drainage, but prefers being planted in the ground.

Seed propagation

1. Collect mature seeds from the dry flower spike.
2. Sow seeds in a well-draining sandy potting mix.
3. Keep the soil lightly moist until germination occurs.
4. Transplant seedlings carefully once they are large enough to handle.

Group with other drought-tolerant Australian natives to ensure consistent water needs.

Grows well with

Banksia · They share similar requirements for well-draining, nutrient-poor soil.
Kangaroo Paw · They provide a striking textural contrast in dry, sunny gardens.

Similar species

Xanthorrhoea australis · It is a closely related species with a similar growth habit and appearance.

Science

Family: Asphodelaceae
Genus: Xanthorrhoea
Order: Asparagales
Class: Liliopsida
Native range: Southwestern Australia
Conservation: This species is protected in its native range and wild collection is strictly regulated.

It is a fire-adapted species that relies on periodic burning to clear competition and stimulate flowering.

Value to wildlife: nectar source, habitat for insects
Pollinators: bees, butterflies, beetles
Uses: ornamental specimen, xeriscaping, coastal garden

Through the year

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Flowering

Fruiting

Foliage

Ecological indicators

Salinity: 4/9
Soil reaction: 5/9
Light: 8/9
Temperature: 7/9
Moisture: 2/9
Nutrients: 1/9

Taxonomy resolved against GBIF.

Questions people ask

How fast does it grow?: It is extremely slow, growing only 1 to 2 centimeters of trunk per year.
Does it need fertilizer?: It is adapted to nutrient-poor soils and generally does not require supplemental feeding.

Where the name comes from

The genus name comes from the Greek words for yellow and flow, referring to the resin. The specific epithet honors the German botanist Ludwig Preiss.

Good to know

It is commonly known as a grass tree.
The trunk is actually a dense accumulation of old leaf bases and resin.
It often flowers more prolifically following a bushfire.
The resin was historically used as a glue by Indigenous Australians.

Also in

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This guide was generated with AI on September 26, 2026 and checked against GBIF taxonomy. It is general information, not horticultural or veterinary advice. Read about how we build these guides.