Eucalyptus smithii

Eucalyptus smithii is part of the "peppermints" group, varieties with highly aromatic foliage, rich in essential oils. Native to south-east Australia, it demonstrates decent hardiness as well as good adaptability to various growing conditions. In its own country it can grow as a bush or form large trees, it reaches an average of about fifteen metres in our latitudes. Its juvenile grey-green foliage turns a slightly glossy green at the adult stage. Its white pom-pom-like flowering and brown to-beige bark are not without interest. Plant in the sun, in moist soil, occasionally humid or dry.

Eucalyptus is part of the vast Myrtaceae family, of which it is one of the most prolific genera with about 800 species recorded. This genus houses different groups with extremely diverse dimensions, ranging from mallees, bushes less than 10 m (32 ft 10 in) branching from the soil, to giants capable of rising to 90 m (295 ft 4 in) height and more, like E. regnans or E. nitens. The Eucalyptus smithii is native to a fairly wide area, which extends from the state of New South Wales to Victoria, in south-east Australia. These regions are characterised by an absence of dry season, mild to hot summers, and winters that can be cold. This forest species grows on plateaus up to 1000 m (3280 ft 10 in) altitude, and lower down towards the coasts. Its natural habitat consists of shallow, neutral to acidic soils, on mountainous slopes.
Eucalyptus smithii is found either as a mallee, mainly in mountainous areas, forming a low bush about 5 m (16 ft 5 in) high, with smooth bark, or as a large forest tree, reaching up to 45 m (147 ft 7 in) in height. This surprising range illustrates the richness of this plant genus. This species also has the peculiarity, quite common among Eucalyptus, of developing a lignotuber, an underground formation rich in starch intended to rebuild the aerial part in case of destruction (especially by fire). It thus has the ability to be able to shoot numerous axillary buds from the stump which then develop in all directions.
When it develops into a tree, it forms a tapered trunk, the upper half of which flares out to form a rather loose and open branching. The very rough grey-brown bark becomes smooth in the upper half. Peeling off in long ribbons, it then has a fairly attractive and decorative light beige surface. The juvenile foliage is formed of rather narrow lanceolate leaves, grey-green in colour. Measuring from 5 to 11 cm (2 to 4.3 in) in length and 0.6 to 2.5 cm (0.2 to 1 in) in width, they are opposite and sessile and the leaf is smooth-edged or slightly dentate. The adult foliage presents alternate and petiolate leaves, much longer and narrower (up to 21 cm (8.3 in) and 1.6 cm (0.6 in) wide). Green, with a slightly shiny surface, they are extremely aromatic. Very rich in eucalyptol, these leaves are used on a large scale in plantations in South Africa for the extraction of essential oils.
Flowering appears in December and January in Australia in the form of small flowers gathered by 7 in axillary umbels. As with other species, it is the white stamens that form small pom-poms, the flowers being petal-less. They then evolve into small brown fruit in the form of capsules, without ornamental interest.
This tree is adaptable and grows in moist soils, occasionally waterlogged, and also resists dryness relatively well once rooted. It is content with shallow, well-drained, neutral to acidic soils and requires a sunny exposure. Its growth is rapid and it resists cold down to about -10°C (14 °F).

Eucalyptus smithii is certainly not the most ornamental species, but it will interest lovers of aromatic foliage, and is quite easy to grow. It will bring a scent of exoticism to the garden. In a coastal climate, plant Gardenia Pinwheel under its shade, very hardy despite its tropical look. Its large star-shaped flowers give off an enchanting fragrance from June to September. Azara microphylla or Chilean Mimosa will also develop well in these conditions, forming a large bush with superb small glossy dark green foliage, and yellow flowering with a vanilla scent in March-April. In slightly drier conditions, try Xanthoceras sorbifolium, an unknown splendour, which takes on the traits of a large bush with spring white flowering with an orange heart, it too has an exotic aspect with its cut-out foliage, which takes on beautiful autumn colours.