Eucalyptus globulus seeds - Blue gum

Eucalyptus globulus, also known as Blue Gum, is one of the most imposing species in the genus and one of the most sought-after for its essential oil. In a Mediterranean climate, by the sea, it quickly reaches an impressive size, forming a beautiful tree in less than 10 years. Its blue-green and decorative juvenile foliage elongates and darkens as it matures. Its creamy-white flowering remains discreet amidst the dense foliage, but its massive trunk is undeniably attractive. This giant thrives best in full sun, in slightly moist but well-drained, non-calcareous or mildly calcareous soils. It makes for a remarkable tree that structures the landscape, reserved for large gardens and parks.

Eucalyptus globulus belongs to the Myrtaceae family. The Eucalyptus genus, mostly native to Australia, comprises over 800 species, including some of the tallest leafy trees in the world, such as Eucalyptus regnans. Eucalyptus globulus is among these giants: in its natural habitat, in south-eastern Australia and Tasmania, it can reach 70 metres in height. Its nickname, Blue Gum, comes from the bluish bloom covering its young leaves. The English call it the "Fever Tree", as it can dry out marshes, thus limiting mosquito proliferation. The species was introduced to southern France in 1860 by botanist Prosper Ramel, where it acclimatised perfectly thanks to mild winters and abundant sunshine. However, its frost tolerance is limited: it can only withstand brief frosts down to around -7°C.
In our southern climates, Blue Gum rarely exceeds 35 metres in height with a 20-metre spread. It displays two types of foliage during its growth. The juvenile foliage consists of ovate, sessile (without a petiole) leaves, 6 to 15 cm long, in a stunning silvery blue. The adult foliage is longer (15 to 30 cm), sickle-shaped, and dark green with a slightly glaucous hue. Its nectar-rich spring flowering often goes unnoticed due to its small size (about 2 cm in diameter), forming creamy-white pompons in the leaf axils. In contrast, its trunk is a true decorative asset: it exfoliates in large patches, revealing smooth bark in varied shades, from beige to cinnamon, including creamy white. There are several subspecies, each with slightly different nuances.

With a rapid growth of 2 metres per year, Eucalyptus globulus can reach 20 metres in just 10 years! This swift development requires careful choice of location, keeping it away from building foundations, as its roots absorb vast amounts of water and may cause long-term issues. Once well-established, it tolerates occasional drought, but its growth remains optimal in sufficiently moist soil.

Eucalyptus globulus is a monumental species, perfect for structuring a vast space while adding a touch of exoticism. Due to its strong competitive ability for water, it is best planted in isolation. However, it can also be paired with other ornamental-leaved trees. For example, with a Gleditsia or Honey Locust. At its base, plant Myrtus communis 'Tarentina' and Liriope, for instance.