Eucalyptus glaucescens Guthega

Eucalyptus glaucescens Guthega quickly takes on the posture of a beautiful specimen in a large garden, low-maintenance and attractive all year round with its particularly decorative barks and its evergreen foliage with bluish hues.  The young foliage is very colourful and aromatic and much appreciated in floral compositions. Its origins from the Australian Alps bring it vigour and robustness, but also an excellent cold resistance capacity. This mountain variety tolerates limestone, but requires moist soil, not too dry in summer. Fast-growing, its installation in the garden requires the choice of a suitable location. In February-March, flowers appear which are rather insignificant, but fragrant and particularly attractive to bees. After this flowering, it tolerates pruning well, and its good regeneration capacities allow it to be grown with a single or multiple trunk.

Eucalyptus glaucescens is a beautiful tree with fairly rapid growth, varying in size depending on where it is located, between 15 and 40 metres (49 feet 2 inches and 131 feet 2 inches). However, in our climates, it rarely exceeds 15 metres (49 feet 2 inches) in height. More commonly named Tingiringi Gum Tree, it belongs to the Myrtaceae family. The species glaucescens is native to the mountainous areas of the far south-east of Australia, on both sides of the border between New South Wales and the state of Victoria in the high altitude areas represented by The Great Dividing Range, the Erica, Hotham, Brumby Point, Tingiringi or Tinderry and Tidbinbilla Ranges near Canberra. The glaucous colour of this eucalyptus' foliage aptly names the species: glaucescens, which comes from the Latin "glaucus" for the blue-green colour and "-escens" which means "becoming". It is recognisable by the white wax coating its branches, floral buds and fruits.

The variety Guthega is named after an Australian ski village and hydroelectric dam, located in Kosciuszko National Park on the upper course of the Snowy River, and the snow-capped mountains of New South Wales. In these harsh regions, it is found on well-drained granitic soils. Vigorous and fast-growing, this gum tree develops several trunks from its base, reaching approximately 15 m (49 ft 2 in) in height and 7 to 9 m (23 to 29 ft 6 in) in width at maturity, depending on the type of soil and climate. Its branching structure, around one or several trunks, forms a wide, fairly dense crown, with a spreading habit. A well-established subject can resist brief frosts of around -15°C (5 °F), but this varies depending on the age of the tree, the duration of the frost and the rise in daytime temperatures, as well as the moisture of the soil.

When young, the Eucalyptus glaucescens Guthega displays numerous pink and reddish branches bearing juvenile foliage composed of rounded silver-blue leaves. At this stage of strong growth, the bark becomes silver-green. Then, as it develops, the leaves take on a lanceolate shape, 8 to 15 cm (3.1 to 5.9 in) long and 3 cm (1.2 in) wide, shiny or dull and glaucous (green to blue-green). The tough leaves are slightly aromatic and release fruity aromas when crushed, rich in eucalyptol. As it ages, the bark is chalky white on its upper part and peels off in long strips, revealing a smooth underlayer, multicoloured in coffee, tin, orange, green, cream and salmon pink. The mature bark of the lower part of the tree is often fibrous and coffee-coloured. Flowering occurs in February-March on plants a few years old. The inflorescence, borne on a short petiole, is composed of 3 floral buds, glaucous or yellow-green, cylindrical, 3 to 5 mm (0.1 to 0.2 in), delicately fragrant and very attractive to bees.

This eucalyptus has a lignotuber, made up of a swelling rich in starch which forms on the roots just below the surface of the soil. This organ allows it to regenerate from the stump in case of severe frost, fire or severe pruning. The plant also produces numerous shoots from dormant buds located under its bark, allowing it to respond very well to coppicing, pollarding or more severe pruning. Note that the alpine gum tree tolerates snow, wind and sea spray. Its root system is not very extensive and therefore less dangerous for buildings and is less competitive with other garden plants. And its vegetation only provides very light shade.

The Tingiringi Gum Tree finds a place in the garden, planted alone, in a clear space, to appreciate the beauty of its barks and the elegance of its foliage. In order to highlight its architectural habit, it is grown with a single trunk or multi-trunks. It tolerates both semi-mountain and semi-arid climates in summer, and its cold resistance will go down to -15°C (5 °F). Comfortable in moist but not swampy soils, it has the ability to dry them out.