shrub

Mullet Creek Grevillea

The Story

Plant Bio

Grevillea shiressii, the Mullet Creek Grevillea, is an evergreen Australian shrub reaching five to sixteen feet in height, featuring glossy, leathery dark green leaves with distinct wavy margins. The unusual spider-like flowers emerge green in bud before transitioning to blue-grey or mauve, contrasted by prominent, long red-brown to maroon styles.

This highly restricted species is endemic to just two catchments north of Sydney, where it naturally occupies moist riparian margins. Unlike dry-land grevilleas, it demands consistent soil moisture and thrives in partial shade, making it highly suited to damp understorey positions.

Uses & Benefits:

Unique blue-grey and maroon spider flowers set against glossy, wavy-margined dark green foliage.

Excellent for stabilizing moist creek banks and understorey screening in humid coastal gardens.

Provides high-quality nectar for native honeyeaters and insect pollinators, while ants disperse the seeds.

Essentials

At a Glance

Plant Type

Shrub

Height

120 inches

Width

96 inches

Light

Full Sun, Partial Sun

Zones

9, 10

Water

Moderate

Humidity

High

Lifespan

10-20 years

Native To

New South Wales, Australia

Toxicity

Non-toxic

Bloom period

Late winter – Spring

In flower about 3 months of the year

Planting

How to Grow

Select a planting site in full sun to partial shade with acidic to neutral, well-draining sandy loam.
Dig a hole twice the width of the root ball and backfill with organic-rich alluvial soil, ensuring the plant sits at its original soil level.
Water deeply and regularly to establish, maintaining consistent soil moisture without allowing the roots to sit in stagnant water.
Apply a thick layer of organic mulch around the root zone to retain moisture, keeping it clear of the main stem.

Pro Tip

Provide reliable moisture while ensuring the soil remains highly permeable; treating this riparian species like a drought-tolerant desert grevillea will cause rapid decline.

Keep It Thriving

Care Guide

Do

Do water regularly during dry spells to maintain the consistent moisture this riparian species requires.
Do apply a low-phosphorus native fertiliser sparingly in spring if nutrient levels are low.
Do tip-prune young plants after flowering to encourage a bushier, denser habit.

Don't

Don't use standard garden fertilisers, as high phosphorus levels are highly toxic to this species.
Don't prune heavily into old, leafless wood, as the plant lacks dormant buds to regenerate from bare branches.
Don't plant in heavy, poorly drained clay soils that trap water and induce root rot.

Seasonal Care Calendar

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

Watch Out For

Pests & Diseases

Common Pests

Common Diseases

In the Garden

Landscape Uses & Companions

Landscape Uses

Riparian restorationUnderstorey screeningBird-attracting habitat gardensMoist, well-drained borders

Companion Plants

Doryanthes excelsa Ceratopetalum gummiferum Tristaniopsis laurina

Multiply

Propagation Methods

Good to Know

Common Questions

Mullet Creek Grevillea questions

What zones can Mullet Creek Grevillea grow in?

Mullet Creek Grevillea 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 Mullet Creek Grevillea bloom?

Mullet Creek Grevillea typically blooms in late winter through spring. Exact timing shifts a week or two with your zone — Sow's bloom calendar maps it to your garden.

Does Mullet Creek Grevillea need full sun?

Mullet Creek Grevillea does best in full sun to part shade. In hot climates, afternoon shade keeps blooms fresher longer.