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Old Man Banksia, Saw Banksia, Wiriyagan

The Story

Plant Bio

Banksia is a genus of Australian evergreen woody plants characterised by dense, cylindrical flower spikes and woody fruiting cones. Banksia serrata develops into a gnarled small tree or large shrub with a thick, twisted trunk covered in corky, grey-brown warty bark.

This species is distinguished by its stiff, oblong leaves with coarsely serrated margins and its large, grey-yellow flower spikes that open to reveal metallic greenish-blue styles. Unlike many other banksias, it lacks a lignotuber, meaning it relies entirely on seed for regeneration after fire or severe damage.

Uses & Benefits:

Features a highly textured, gnarled trunk with corky bark and architectural flower spikes.

Acts as an effective windbreak and soil stabiliser in sandy, coastal environments.

Provides abundant nectar for honeyeaters, native bees, possums, and sugar gliders.

Essentials

At a Glance

Plant Type

Tree

Height

393 inches

Width

236 inches

Light

Full Sun, Partial Sun

Zones

9, 10

Water

Low

Humidity

Moderate

Lifespan

Decades

Native To

Eastern Australia

Toxicity

Non-toxic

Bloom period

Summer – Autumn

In flower about 4 months of the year

Planting

How to Grow

Select a planting site in full sun to partial shade with exceptional drainage, such as sandy soil or gravelly sandstone.
Dig a hole twice the width of the root ball but of equal depth, ensuring the plant sits at the same soil level as it did in the pot.
Water the plant in thoroughly to settle the soil, avoiding any heavy organic mulches directly against the trunk.
Establish a strict watering regime during the first dry season, then reduce watering significantly once the taproot is established.

Pro Tip

Never prune back into old, leafless wood; because this species lacks a lignotuber, cutting past the green foliage will prevent epicormic shooting and kill the branch.

Keep It Thriving

Care Guide

Do

Ensure the soil has exceptional drainage before planting.
Use only native-specific, low-phosphorus fertilisers.
Plant in a position with full sun and good airflow.

Don't

Do not prune back into old, leafless, brown wood.
Do not plant in heavy clay or waterlogged soils.
Do not use standard high-phosphorus garden fertilisers.

Seasonal Care Calendar

Task	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Fertilize
Pest Check
Propagate
Prune

Watch Out For

Pests & Diseases

Common Pests

Common Diseases

In the Garden

Landscape Uses & Companions

Landscape Uses

Coastal windbreakSpecimen plantingWildlife garden

Companion Plants

Leptospermum laevigatum Correa alba Anigozanthos flavidus

Multiply

Propagation Methods

Good to Know

Common Questions

Old Man Banksia, Saw Banksia, Wiriyagan questions

What zones can Old Man Banksia, Saw Banksia, Wiriyagan grow in?

Old Man Banksia, Saw Banksia, Wiriyagan is hardy in USDA Zones 9–10. Inside that range it survives winter in the ground; outside it, grow it as an annual or a container plant you protect.

When does Old Man Banksia, Saw Banksia, Wiriyagan bloom?

Old Man Banksia, Saw Banksia, Wiriyagan typically blooms in summer through autumn. Exact timing shifts a week or two with your zone — Sow's bloom calendar maps it to your garden.

Does Old Man Banksia, Saw Banksia, Wiriyagan need full sun?

Old Man Banksia, Saw Banksia, Wiriyagan does best in full sun to part shade. In hot climates, afternoon shade keeps blooms fresher longer.

Is Old Man Banksia, Saw Banksia, Wiriyagan drought tolerant?

Yes — once established (usually after the first full season), Old Man Banksia, Saw Banksia, Wiriyagan handles dry spells with minimal watering. Water deeply its first year to build the root system that makes that possible.