Garden hybrid

This is a garden hybrid, bred from more than one wild species, so it has no single species page of its own.

1 other cultivar

‘Wynyabbie Gem’Coast Rosemary

shrub

Blue Gem Coast Rosemary

Westringia x hybrida 'Blue Gem'

The Story

Plant Bio

Westringia is a genus of evergreen shrubs endemic to Australia, closely related to rosemary and adapted to coastal cliffs and sandy soils. These plants feature narrow, leathery leaves arranged in tight whorls along the stems and produce small, two-lipped tubular flowers.

'Blue Gem' is a compact, upright hybrid cultivar distinguished by its dark maroon-brown stems and exceptionally vivid bluish-purple flowers. It maintains a denser, bushier habit than the species and tolerates tight shearing without developing woody interior gaps.

Uses & Benefits:

Provides year-round structure, fine-textured gray-green foliage, and vivid purple flowers suitable for formal hedges or coastal accents.

Offers exceptional drought tolerance, wind resistance, and salt tolerance, making it ideal for low-maintenance or coastal landscapes.

Attracts generalist native bees, butterflies, and other beneficial insect pollinators with its long-blooming flowers.

Garden hybrid

Bred from more than one wild species, so it has no species page of its own.

Essentials

At a Glance

Plant Type

Shrub

Height

72"

Width

48"

Light

Full Sun, Partial Sun

Zones

9, 10

Water

Low

Humidity

High

Lifespan

10-15 years

Native To

Australia

Toxicity

Non-toxic

Bloom period

Spring – Year round

In flower about 10 months of the year

Planting

How to Grow

Select a planting site in full sun to very light shade with exceptionally well-drained sandy or loamy soil.
Dig a hole twice as wide as the root ball but equal in depth, ensuring the crown sits slightly above the surrounding soil level.
Water deeply immediately after planting, then transition to infrequent, deep watering once the root system establishes.
Apply a light layer of organic mulch around the base, keeping it several inches away from the main stems to prevent rot.

Pro Tip

Prune the shrub immediately after the heavy spring flowering flush to maintain its tight, dense form; cutting back into old, leafless wood often prevents new shoots from developing.

Keep It Thriving

Care Guide

Do

Plant in exceptionally well-drained soil
Prune regularly after flowering to maintain density
Water deeply but infrequently once established

Don't

Do not allow the roots to sit in standing water
Avoid cutting back into old, leafless wood
Do not over-fertilize, especially with high-nitrogen products

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

HedgesCoastal GardensMediterranean GardensMass PlantingsContainers

Companion Plants

Rosmarinus officinalis Lavandula dentata Salvia clevelandii

Multiply

Propagation Methods

Good to Know

Common Questions

Blue Gem Coast Rosemary questions

What zones can Blue Gem Coast Rosemary grow in?

Blue Gem Coast 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 Blue Gem Coast Rosemary deer resistant?

Not reliably. Deer may browse Blue Gem Coast Rosemary, especially tender spring growth — plan on repellents or fencing where pressure is high.

When does Blue Gem Coast Rosemary bloom?

Blue Gem Coast Rosemary typically blooms in spring through year round. Exact timing shifts a week or two with your zone — Sow's bloom calendar maps it to your garden.

Does Blue Gem Coast Rosemary need full sun?

Blue Gem Coast Rosemary does best in full sun to part shade. In hot climates, afternoon shade keeps blooms fresher longer.

Is Blue Gem Coast Rosemary drought tolerant?

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