Westringia fruticosa - Australian Rosemary: Planting, Growing and Care

Description and botany

Westringia or Australian rosemary is a bush from the Lamiaceae family, just like sage, mint or even rosemary to which it is very similar. It grows naturally in the coastal heathlands of eastern Australia and southern New South Wales. Less hardy than our rosemary, it prefers mild climates and adapts easily to regions with gentle winters (coastal, Atlantic and Mediterranean areas). The genus includes about 25 species, the most widespread being Westringia fruticosa. The type species has given rise to a few cultivars, including Westringia fruticosa ‘Mundi’ which stands out for its white flowering and low, ground-covering habit.

The fine, silvery foliage of Westringia fruticosa (photos: Drew Avery / Bri Weldon)

From a woody stump, the Australian rosemary forms a dense bush with a rounded, slightly spreading habit, ranging from 50 cm to 3 m in all directions, depending on the variety and growing conditions. The woody, square-sectioned branches bear evergreen foliage. It consists of small, linear, lanceolate and rigid leaves, resembling needles 1.5 to 2.5 cm long. They are less tough than those of rosemary and arranged in whorls of 3 to 4 on the woody branches. They are edged and green to grey-green on the upper side, downy and greyish-white underneath. They are margined with white in Westringia fruticosa ‘Smookie’. Very similar to those of rosemary, they are however not aromatic.

Flowering occurs from May to September, sometimes even all year in successive waves, but more sporadically. The bilabiate flowers are typical of the Lamiaceae family. Tubular, they open into 2 lobes for the upper lip and 3 lobes for the lower lip. Quite large, measuring up to 1.5 cm in diameter, they bloom singly at the ends of the shoots, inserted in the axil of the leaves. These delicate flowers are usually pale blue speckled with purple at the throat, more rarely white.

This fragrant, melliferous and nectariferous flowering attracts many pollinating insects from spring to summer.

The delicate flowering of Westringia fruticosa

Main species and varieties

[product sku=”100901″ blog_description=”A white-flowered variety that forms a very good, dense ground cover.” template=”listing1″ /]

[product sku=”186971″ blog_description=”A cultivar distinguished by green foliage marginate with white.” template=”listing1″ /]

[product sku=”83476″ blog_description=”Here is a more compact, white-flowered form of the Australian Rosemary.” template=”listing1″ /]

[product sku=”83475″ blog_description=”This is the type species with its beautiful mauve flowering and evergreen green foliage!” template=”listing1″ /]

Planting the Australian rosemary

Where to Plant Australian Rosemary?

Naturally growing on Australian coastal heathlands, the Westringia thrives easily in gardens along the Atlantic or Mediterranean coast. Relatively frost-sensitive (down to -5/-6°C once well established), it will do well in pots in colder regions. It is perfectly equipped to handle drought and also tolerates sea spray in coastal gardens very well. It enjoys warm, sunny exposures, tolerating partial shade in the most exposed regions. It prefers light, stony, sandy, poor, and especially very well-drained soils. In reality, it is not very demanding regarding soil type and will even grow in clayey and loamy soil. It’s an excellent candidate for dry areas, where it forms an evergreen bush all year round.

It works well as an accent in a bed with other mild-climate bushes, or in a beautiful seaside hedge, left free or pruned. It can also be planted on a dry, sunny slope or in a pot to overwinter frost-free in colder, wetter regions. And, since it tolerates regular pruning well, it can be shaped into topiary according to your preferences.

When to Plant Australian Rosemary?

Westringia is best planted in spring, after the last frosts, or in autumn, from September to October.

How to Plant?

In heavy soil, incorporate gravel or coarse sand at the bottom of the planting hole to improve drainage. In very chalky soil, it’s best to add heather soil or peaty compost at planting time.

In the ground

• Dig a planting hole about 60 cm in all directions. Ideally, it should be two to three times the size of the root ball.
• Optionally, place gravel or coarse sand in the hole, mixed with the planting soil, to improve drainage.
• Remove the Westringia from its pot and place it in the centre of the planting hole.
• Fill in with the excavated soil, optionally mixed with sand, then lightly firm down.
• All that’s left is to water generously.

Ensure successful planting of your Westringia by following our advice in our video “How to Plant a Bush”.

In pots

Westringia adapts very well to pot cultivation in a well-draining substrate to avoid waterlogging around the roots.

• In a container at least 50 cm in diameter, place a layer of gravel or clay pebbles at the bottom.
• Plant in a mix of garden soil or Mediterranean plant compost and non-chalky sand.
• Water at planting time, then moderately thereafter.
• In colder regions, remember to bring the pot under cover for winter.

Maintenance, pruning and care

Once established, the Westringia requires little maintenance. It is drought-resistant once well-rooted. Monitor watering during the first two summers. After that, water only during prolonged dry spells and always sparingly. Regular but spaced-out watering will nevertheless support its flowering. In pots, ensure more consistent watering while always allowing the substrate to dry out between waterings.

Mulch the base with mulch or dry leaves to limit weed growth. In regions north of the Loire, bring potted specimens indoors before the first frosts.

The Westringia is highly resistant to diseases and parasites.

When and how to prune the Westringia?

The Westringia can be left to grow freely or pruned to control its size. Annual pruning stimulates flowering and encourages a dense habit. This should be done at the end of winter, in March, outside frost periods. Light pruning, aimed at removing dead or diseased branches and shaping the plant to your preference, is usually sufficient. After flowering, trim spent stems with secateurs. If you wish to prune more severely to limit its height in a hedge, for example, do so just after the peak of the main flowering period.

The Westringia can also be topiary-pruned, as its rounded and dense habit allows for very regular shapes to be formed.

Propagation

The easiest method to propagate Australian rosemary is through propagation by cuttings of semi-lignified stems, after flowering. Sowing with seeds harvested in autumn is also possible in spring on a warm and humid bed.

• In September, cut lignified, flowerless stems approximately 10 to 15 cm long.
• Remove the lower leaves.
• Plant the cuttings in a mix of compost and sand or perlite to ensure good drainage.
• Keep the substrate slightly moist and place the cuttings in a frost-free, bright location, avoiding direct sunlight.
• Roots should begin to develop after a few weeks.
• Transplant the cuttings into individual pots before moving them to the garden the following spring.
• Water well during the first year after planting.

→ Learn more in our tutorial: How to propagate Westringia?

How to pair Australian rosemary?

Pair Westringia with plants that share its cultivation needs to create a drought-resistant and low-maintenance garden. It will easily find its place in dry gardens and coastal settings alongside drought-resistant perennials and Mediterranean perennials. In a flower bed, it will thrive alongside sages, Helichrysum italicum, Rockrose, Lavender Cotton, sunroses, artemisias, and sedums. Of course, it will be the perfect companion for its cousin, rosemary, both remaining attractive even in winter.

It is also ideal for pairing with Mediterranean bushes such as ceanothus, mimosas, oleanders, Callistemon, Leptospermum, or grevillea.

Westringia fruticosa, Santolina chamaecyparissus, Oleander, Lavandin (Lavandula intermedia Dutch group), Sunrose ‘Elfenbeinglanz’