Southern Blue Gum
Eucalyptus globulus subsp. bicostata
Southern Blue Gum (Eucalyptus globulus subsp. bicostata) is a fast-growing, iconic Australian eucalypt native to the cool mountain regions of southeastern Australia, including parts of Victoria, New South Wales, and Tasmania. Known for its towering form, smooth bluish bark, and strongly aromatic foliage, it is one of the most widely cultivated eucalyptus species in the world.
In ideal conditions, this evergreen tree can reach up to 70 m in height, though more commonly grows to 15–25 m in cultivation. Juvenile foliage is strikingly blue-green and rounded, maturing to long, lance-shaped adult leaves rich in eucalyptus oil. Creamy white flowers bloom from winter to early summer, supporting native pollinators and beneficial insects.
Best suited to large rural gardens, farms, revegetation sites and shelterbelts, this species is too large for suburban spaces. Its vigorous root system requires careful siting away from buildings and underground infrastructure.
- Tall, evergreen eucalyptus tree | 15–25 m H (up to 70 m in forest conditions)
- Smooth, powdery blue-grey bark | Sheds in long ribbons | Rough bark near base
- Blue-green juvenile foliage | Fragrant lance-shaped adult leaves
- White flowers from winter to early summer | Attracts birds, bees and native insects
- Grows in cool, temperate climates | Tolerates frost and moderate drought
- Fast-growing | Strong root system | Coppices well after cutting or fire
- Excellent for windbreaks, shelterbelts, firewood, and large-scale revegetation
- Not suitable for small gardens or planting near pipes or foundations
Landscaping & Garden Use
Southern Blue Gum is ideal for large-scale landscaping, bushland restoration, and open gardens where its dramatic height and blue-toned foliage can be fully appreciated. The juvenile leaves are highly ornamental and often harvested for floral work or dried arrangements. Its dense canopy provides wind protection, fast-growing shade, and long-term shelter.
Ecological Value
This eucalyptus species is important for supporting biodiversity. Its flowers provide winter nectar for birds, bees and insects, while the shedding bark and tall structure offer shelter and habitat for wildlife. In exposed or poor soils it may adopt a shrubbier form but maintains strong coppicing ability and soil-stabilising roots.
Practical & Cultural Uses
Southern Blue Gum is grown globally for its versatile timber, used in railway sleepers, structural posts, paper production, and firewood. Though it produces a relatively low yield of eucalyptus oil, its leaves and branches are still harvested for medicinal and fragrance applications. The wood has a strong, open grain with distinct growth rings and is suitable for biomass and coppiced fuel.
One of the most recognisable Australian native trees, Southern Blue Gum is valued for its fast growth, towering form, and many ecological and practical benefits.
