Westringia glabra

Westringia glabra, more commonly known as Australian Rosemary, bears a resemblance to our Mediterranean shrub. Both belong to the same botanical family, Lamiaceae. With rapid growth, Westringia develops a well-branched, fairly regular habit. Its dark green, very fine foliage forms an ideal background for its long-lasting pale mauve flowers. The low hardiness of this bush limits it to mild coastal areas, where it tolerates dry summers well. Elsewhere, it can easily be grown in containers to add a Mediterranean touch to the terrace. It should be brought indoors during winter.

Westringia belongs to the Lamiaceae family, which includes 6,000 species, many of which are aromatic plants (Mint, Lavender, Basil...). Like all Westringia species (25 in total), W. glabra is native to Australia, where it grows naturally in the southeastern part of the continent.
It is a fast-growing shrub, typically taking no more than three seasons to reach its mature size. It more or less forms a ball 1.25 m to 1.50 m in diameter. It can grow slightly taller to form a rounded cone shape. Its stems are square in cross-section, typical of Lamiaceae, green when young, then turning brown as they turn woody and harden. The foliage is very dense, with numerous main stems that branch generously, making it an excellent low hedge plant, which also tolerates pruning well. The lanceolate leaves are very small, about 1.5 cm long and a few millimetres wide. They are usually grouped in whorls of four, forming tiers along the stems. Each leaf is attached to one of the four sides of the stem, giving the shrub a distinctive sculptural appearance. They are dark green, occasionally slightly bluish, and their surface is somewhat rough and leathery. The reduction in leaf surface area, as is often the case with plants, is a good indicator of drought resistance.
Flowering begins to appear in March in the mildest regions and continues throughout spring until early summer, sometimes even longer in certain years. The flowers are sometimes solitary but more often grouped in whorls, similar to the leaves. They measure approximately 2 cm long and have a typical morphology, known as bilabiate, with an upper lip slightly split into two lobes, while the lower lip is divided into three lobes, the central one slightly larger than the two lateral ones. Their colour varies between a blue-mauve and a lilac-mauve, always pale. The throat is also dotted with small, darker spots, highlighting the unique shape of the corolla. The flowers are quite numerous but do not create a mass effect due to their small size. The flowering is not spectacular, but it is nevertheless pleasant and has the merit of lasting a long time.

Westringia glabra is a shrub suited to the south and mild western areas, as it can die at temperatures below -5°C, especially if the soil is not well-draining. Apart from this limitation, it proves very easy to grow in most soils. However, it tolerates sea spray slightly less well than Westringia fruticosa, which it closely resembles visually. Plant it as a low hedge, which you can prune as desired once a year, or in a bed alongside other "Mediterranean" plants. It pairs well with Oleander (Nerium oleander), whose flowering will take over from its own in a wide range of colours depending on the variety you choose. Also consider varying the foliage with a Ceanothus impressus 'Lemon & Lime', variegated in yellow and green, which produces intense blue flowers in spring. In the background, a dark-leaved Crape Myrtle, such as Lagerstroemia indica 'Black Solitaire', which has bright pink flowers all summer, will create a stunning scene.