The genus Westringia belongs in the mint family Lamiaceae. There are 25 species in the genus and all are endemic to Australia. They are shrubs with angled stems. The leaf arrangement is usually whorls of 3 to 5 small leaves. Westringias are suited to various soil types, including sandy and rocky areas. Most species occur in heath- and scrub-lands, in coastal areas or in forests. The tubular flowers have upper and lower ‘lips’, the upper lip having two lobes with three lobes on the bottom. Flowers appear in the axils of the leaves and last over a long period of time. They make attractive plants for areas with mild winters and are useful when a screen or hedge is needed.
Westringia brevifolia or short-leaved westringia is native to Tasmania. It grows to about 1.5 metres with a similar spread. The small leaves are arranged in whorls of four and are an attractive silver-grey. The pale mauve flowers appear in winter and spring. It will grow in sun or part shade and is suited to coastal regions. It is generally regarded as suitable for zones 8 to 11.
Westringia eremicola is a widespread species, sometimes called the slender western rosemary or slender westringia. It is common throughout South Australia, Queensland, New South Wales and Victoria. The leaves are narrow but may be elliptic or linear in shape with the margins rolled under. The main floral display is in summer although flowers are produced throughout the year. The flowers are usually mauve or lilac but are very occasionally white.
Another westringia with ‘rosemary’ in its common name is Westringia fruticosa, also known as coast rosemary, Australian rosemary or native rosemary. The leaves of some species are like those of the herb rosemary hence the name. This species is from eastern coastal Australia and forms a dense mound. The dark green leaves grow to 3cm and are a shiny dark green on the upper surfaces and a paler, felted green below. The flowers are white with the bottom lobes dotted with purple or brown. It flowers through most of the year with the main display being from September to November. It is very hardy with many landscape uses. It is tolerant of wind and salty air so is an ideal choice for seaside gardens.
A variegated form, W.fruticosa ‘Morning Light’, is available but it is less vigorous than forms with green foliage.
Westringia glabra (violet westringia) has pale purple to violet flowers with maroon dots. It flowers year round with its display peaking in spring. The leaves are narrow-elliptic to lance shape.
A popular variety is W. ‘Wynyabbie Gem’, a hybrid between W.eremicola and W.fructicosa. This is a bushy shrub which grows to 1.2 metres and has fine, dark green leaves. It flowers through most of the year bearing small bluish pink flowers at the tips of the branches. It does not always live for very long.
Westringias like well-drained soil. They will tolerate light shade, salty winds and exposed conditions. However they do need watering in summer. They can be pruned after flowering to maintain a nicely compact shape. Propagation is by cuttings.
