Eucalyptus sideroxylon

Eucalyptus sideroxylon, also known as the Mugga gum tree, or more imaginatively, the Ironbark Eucalyptus, is known for its extremely resilient bark. With rapid growth, it forms a beautiful medium-sized tree, with well-distributed vegetation, whose grey-green leaves form a beautiful contrast with the very dark bark. The autumnal flowering is also very ornamental, consisting of small, abundant pom-pom flowers grouped in umbels. Their colour varies according to the origin of the seeds, some plants flowering white, others pink or red. This species resists frost quite well and tolerates many types of soil, provided it benefits from good drainage and a sunny location.

Eucalyptus sideroxylon is a member of the vast Myrtaceae family, which includes approximately 130 genera of plants from tropical and warm temperate regions. Many of them are abundantly planted in gardens (Callistemon, Leptospermum, Myrtus...), like the Eucalyptus of which there are 800 species, almost all originating from Australia.
The natural range of E. sideroxylon thus extends from the northeast of the state of Victoria (all the way south of Australia) to the south of Queensland (Brisbane region) crossing all the east and centre of New South Wales. This vast area is home to various climates, temperate with or without dry season, semi-arid and mild subtropical. This probably explains the great adaptability of this species, also characterised by the development of a lignotuber. This is an underground swelling rich in starch that allows the plant, in case of destruction of the aerial part (fire, animal predation...), to be able to restart from the stump. Axillary buds develop and then regrow the plant.
In its natural habitat, this fast-growing Eucalyptus forms a tree reaching 25 m (82 ft) in height. It is easily recognisable by its almost black, deeply fissured bark, reputed to be hard as iron. This characteristic inspired its species name (in Greek sideros means iron and xylon, bark) as well as its vernacular name of Ironbark (or Red Ironbark). This beautiful tree, with harmonious proportions, adopts a well-branched, erect habit, with a fairly dense crown, with a rounded top. There is a juvenile foliage, with opposite petiolate oblong leaves, measuring up to 11 cm (4.3 in) long and 3.5 cm (1.4 in) wide, green, bluish or greyish in colour. The adult foliage is composed of alternate lanceolate leaves, 5 to 14 cm (2 to 5.5 in) long and 1 to 4 cm (0.4 to 1.6 in) wide, blue-green or grey-green. The overall glaucous to greyish appearance of the trailing foliage contrasts pleasantly with the very dark colour of the bark.
The flowering is also very aesthetic, consisting of umbels of 2 to 7 floral buds, which open into clusters of stamens resembling small pompons of 1 to 2 cm (0.4 to 0.8 in) in diameter. The abundant flowers can be white, yellowish, pink or red, as this species shows marked genetic variability. This is also reflected in a fluctuating flowering period, spreading between April and December in Australia, and generally between September and December in the UK.
Growing in neutral to acidic soils, this Eucalyptus tolerates lime quite well, accepting poor and even dry soils. Its only requirement is well-drained soil, as it fears excess water. It also needs a sunny exposure, especially in cool climates. Its hardiness is -10°C (14 °F), under good conditions, i.e. in dry soil as stagnant humidity accentuates the effects of the cold. In Mediterranean climates it reaches approximately 17 to 18 m (55 ft 10 in to 59 ft 1 in) in height, and will adapt well to hot, dry summers and mild winters.

Eucalyptus sideroxylon is certainly a good choice for the garden for its ornamental qualities and for its hardiness. Its flowers will appear after 6 or 7 years. Its exotic appearance will blend well with other plants of a similar type such as the Acacia boormanii, a small mimosa with very fine foliage and a magnificent yellow flowering in February. Melia azedarach Jade Snowflake, or Variegated Chinaberry, is an easy-to-grow small tree whose pretty green foliage marbled with cream white will create a nice contrast with that of our Eucalyptus. To enjoy an original summer flowering, plant Buddleia weyeriana Sungold, a butterfly tree with unique orange-yellow flowers, which will form a strong contrast in front of the black bark of the Eucalyptus.