Eucalyptus urnigera

Eucalyptus urnigera, commonly known as the urn gum tree, is a mountain species from Tasmania, known for its good hardiness. This small tree with moderate growth is distinguished by its beautiful light bark that displays different tones. This is the glaucous form, with stunning bluish evergreen foliage. The juvenile foliage, composed of almost round opposite leaves, is particularly attractive. This Eucalyptus produces small white pompon flowers, blooming at various times of the year, but usually towards the end of summer. Thriving in sunlight, in most soils except for those that are too chalky, it is well adapted to coastal climates.

Eucalyptus urnigera is an endemic species from Tasmania, where it mainly grows in the southeastern part of the island and in a few isolated locations. It can be found in mountainous areas, from mid-slope to over 1000 metres (3280 feet 10 inches) in altitude, growing in shallow soil among rocky outcrops, on mountain tops, and in sparse woods. Like all Eucalyptus, it belongs to the large family of Myrtaceae, which includes many ornamental genera (Callistemon, Chamaelaucium, Melaleuca, etc.). The green form of E. urnigera is more commonly found at low altitudes, while the glaucous form prefers high elevations and mountain tops. This species - like many other Eucalyptus - develops a lignotuber, a starch-rich swelling at the base of the partially underground trunk, which allows buds to regenerate after a fire. This adaptation to local conditions explains why most species regenerate well after pruning, even severe pruning, rejuvenating the plants by promoting the growth of young shoots.
With moderate growth and development, this Eucalyptus forms a tree of about 12 metres (39 feet 5 inches) in height (often less in our climates), with a relatively narrow habit in its natural environment due to the competition from surrounding plants. It tends to reach for the light it craves by stretching upwards, leaving the lower part of the trunk bare and supporting a slightly spreading canopy in the upper part. When planted in isolation, it will form a wider crown with better branching throughout the height of the tree. The smooth bark displays a range of colours, combining white with light grey, yellow, and some shades of brown. It regularly peels off in long ribbons that fall to the ground at the base of the tree.
The foliage is also a strong ornamental feature of this species, especially in the glaucous form. The juvenile foliage is bluish rather than green, with small almost round leaves measuring 2 to 3 cm (0.8 to 1.2 in) in diameter. Sessile and opposite, they enclose the young stems, which are also bluish. The adult foliage has a different morphology, as is often the case with Eucalyptus. The leaves are alternate and petiolate, elongated to slightly elliptical in shape, measuring 3.5 to 9 cm (1.4 to 3.5 in) in length and 1 to 2.8 cm (0.4 to 1.1 in) in width. They are also blue-green and aromatic due to the oil-rich glands located at the intersections of the veins on the lamina.
The classic flowering consists of small petal-less flowers, with decorative stamens. These white flowers are grouped in threes, in the axils of the leaves, and appear in Tasmania almost anytime throughout the year, with a more pronounced peak from April to July. In our climates, they generally bloom towards the end of summer, but their relatively small size makes them less of an event. The small fruits that follow have a curious urn-like shape, which gave this species its name. They have no ornamental value.
Eucalyptus urnigera grows in rocky soils, in neutral to acidic or even alkaline, as long as they do not contain too much active limestone. It requires sunlight and appreciates moist soils, even tolerating temporary flooding. It is hardy down to -15°C (5 °F) in well-drained soil. It is not well-suited to dry conditions, although once well-rooted, it can withstand periods of drought.

This Eucalyptus is a real find for exotic plant enthusiasts. One of the hardiest alongside the Eucalyptus niphophila (aptly named Snow gum), it allows you to create a southern atmosphere even in cool climates. Typically reaching a height of 7 to 8 metres (23 to 26 feet 2 inches) in our climates, it is perfect for small gardens. Plant it alongside other evocative plants such as hardy palm trees: Trachycarpus wagnerianus with its graphically shaped fronds and fibrous trunk will blend perfectly with the urn gum tree to create a dreamlike scene. The lesser-known Rhapidophyllum hystrix, with its spiny trunk, and Sabal minor, whose leaves emerge directly from the ground, will also create a unique atmosphere.