Species

Westringia fruticosaCoastal Rosemary

5 other cultivars

shrub

Grey Box Coastal Rosemary

Westringia fruticosa 'Grey Box'

The Story

Plant Bio

Westringia fruticosa, commonly known as coastal rosemary, is an evergreen Australian shrub native to the coastal cliffs of New South Wales. It features narrow, leathery leaves and small, two-lipped flowers that tolerate harsh salt spray and persistent coastal winds.

'Grey Box' is an ultra-compact, naturally ball-shaped selection distinguished by its tight, densely branched habit and striking silvery-grey foliage. Unlike the parent species, this cultivar tolerates heavy clay soils and periodic wet feet once established, making it a highly adaptable alternative to English boxwood.

Uses & Benefits:

Provides a tight, naturally spherical form with fine-textured, silvery-grey foliage that serves as an excellent low hedge or structural accent.

Offers exceptional drought, wind, and salt tolerance, and uniquely tolerates periodic wet soil conditions once established.

Provides nectar for native bees, beneficial insects, and occasional hummingbirds with its small white flowers.

SpeciesWestringia fruticosaCoastal Rosemary

Essentials

At a Glance

Plant Type

Shrub

Height

36"

Width

36"

Light

Full Sun, Partial Sun

Zones

9, 10

Water

Low

Humidity

High tolerance

Lifespan

10-15 years

Native To

Australia

Toxicity

Non-toxic

Bloom period

Spring – Autumn

In flower about 9 months of the year

Planting

How to Grow

Select a planting site in full sun to light shade with well-drained soil, though heavy clay is acceptable.
Dig a hole twice as wide as the root ball and of equal depth, ensuring the crown sits level with the surrounding soil.
Water regularly for the first eight to thirteen weeks to establish a deep, resilient root system.
Apply a thick layer of chunky organic mulch around the base of the plant, keeping it clear of the main stem to prevent rot.
Prune lightly after the main flowering flush to maintain a neat, compact shape.

Pro Tip

Avoid shearing deeply into old, leafless wood, as Westringia regenerates poorly from bare stems; instead, light tip-pruning one to three times a year maintains the tight, spherical form.

Keep It Thriving

Care Guide

Do

Water consistently during the initial three-month establishment phase.
Apply a chunky organic mulch to retain soil moisture and suppress weeds.
Prune up to three times a year to maintain a formal, rounded shape.

Don't

Do not cut back into old, bare wood lacking green foliage.
Do not over-fertilize, as this cultivar requires minimal nutrients to thrive.
Do not pile mulch directly against the main stem.

Seasonal Care Calendar

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

Watch Out For

Pests & Diseases

Common Pests

Common Diseases

In the Garden

Landscape Uses & Companions

Landscape Uses

Low HedgeBorder EdgingBioswalesMass PlantingCoastal GardensContainer Planting

Companion Plants

Rosmarinus officinalis Salvia clevelandii Lomandra longifolia Agave attenuata

Multiply

Propagation Methods

Good to Know

Common Questions

Grey Box Coastal Rosemary questions

What zones can Grey Box Coastal Rosemary grow in?

Grey Box Coastal Rosemary 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.

Is Grey Box Coastal Rosemary deer resistant?

Not reliably. Deer may browse Grey Box Coastal Rosemary, especially tender spring growth — plan on repellents or fencing where pressure is high.

When does Grey Box Coastal Rosemary bloom?

Grey Box Coastal Rosemary typically blooms in spring through autumn. Exact timing shifts a week or two with your zone — Sow's bloom calendar maps it to your garden.

Does Grey Box Coastal Rosemary need full sun?

Grey Box Coastal Rosemary does best in full sun to part shade. In hot climates, afternoon shade keeps blooms fresher longer.

Is Grey Box Coastal Rosemary drought tolerant?

Yes — once established (usually after the first full season), Grey Box Coastal Rosemary handles dry spells with minimal watering. Water deeply its first year to build the root system that makes that possible.