Eucalyptus globulus Seeds | Tasmanian Blue Gum
LATIN NAME: Eucalyptus globulus
COMMON NAME: Tasmanian Blue Gum
Plant Profile
Eucalyptus globulus is the gum tree of the blue hills of Tasmania, and it is one of the fastest-growing trees in the world. It reaches seventy metres in the wild, with a straight trunk and a crown of long, drooping, blue-green leaves, and the bark peels in long ribbons from the upper trunk and hangs in strips. The juvenile leaves are opposite, glaucous and rounded, and they are the ones sold in floristry.
The species is native to Tasmania and to southern Victoria, in wet forest and in valleys, and it has been planted throughout the world for pulp, for oil and for timber. It is the main hardwood pulp species of Portugal, Spain, Brazil, Chile and China, and it is also one of the most widely planted invasive trees outside its range.
Science & Biotechnology
The leaf contains an essential oil dominated by 1,8-cineole, together with pinene and limonene, and the oil is distilled for use in medicine, in flavouring and in cleaning products. The oil is toxic in quantity, and ingestion of the neat oil has caused seizures in children. The tree also produces allelopathic compounds that suppress understorey plants, which is part of why its plantations are bare underneath.
The species is adapted to fire. It has lignotubers that resprout after being burnt, and the seed is released from woody capsules after a fire. It also uses a lot of water, and plantations have been criticised for reducing stream flow and for lowering water tables, a point that matters in dry regions where the tree is grown.
Uses & Benefits
The wood is used for pulp, for paper, for poles and for flooring, and the oil is distilled from the leaves for pharmaceutical and industrial use. The tree is planted for windbreaks, for shade and for land reclamation, and the juvenile foliage is used in floristry.
In medicine the oil is used as an inhalant for coughs and as a rub for chest complaints, and the leaf is used in a tea. The oil should not be taken internally, and it should not be used on the face of a young child, since it can cause laryngospasm.
Growing from Seed
Seed is tiny and germinates readily. Surface-sow on a moist mix at 20 to 25 degrees, and seedlings appear in one to three weeks. Plant out when the seedling is twenty centimetres high, since the taproot develops quickly and resents disturbance.
The tree wants full sun and a deep soil, and it tolerates drought once established. It is hardy to about minus seven, though it is damaged by hard frost when young. It grows very fast and very tall, so do not plant it near a house, a drain or a boundary, and be aware that it can suppress everything beneath it.
Our Take
A fast, tall, useful tree that is also a thirsty and invasive one. Plant it where its size, its litter and its water use are not a problem.
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