Common Name: Narrow-Leaved Peppermint

General Information

Eucalyptus radiata is an evergreen tree with a spreading, drooping crown; it can grow from 10 - 30 metres tall, sometimes reaching 40 metres. The bole is usually short, up to 100cm in diameter. Growing in open conditions the smaller trees often retain foliage to near ground level[, , ].
The tree is harvested from the wild as a commercial source of wood and essential oils. This is a valuable species for providing shelter and for ornament, where it is often coppiced annually to produce vigorous young shoots[, ].

Known Hazards

None known

Botanical References

,

Range

Australia - Victoria, New South Wales

Habitat

Mixed forests on a variety of soils; at elevations from 150 - 1,000 metres[].

Properties

Medicinal Rating
Other Uses Rating
Habit	Evergreen Tree
Height	20.00 m
Growth Rate	Fast
Pollinators	Bees, Insects
Cultivation Status	Cultivated, Ornamental, Wild

Cultivation Details

Eucalyptus radiata is native to the warm temperate climate of eastern Australia, where it is found at elevations from 150 - 1,000 metres. Rainfall can occur all year round or only in the winter, with a mean annual rainfall within the range 625 - 1,250mm and a dry season that is not usually severe of up to 4 months. The mean maximum temperature of the hottest month is 23°c; mean minimum temperature of the coldest month is 0 - 5°c, and there are generally around 15 - 80 frosts a year[]. When dormant, the plant can survive temperatures down to about -10°c, but young growth is more tender and can be severely damaged at -1°c[].
Requires a sunny position, succeeding in a range of light to medium-textured, well-drained soils of high fertility[]. Prefers a pH in the range 5.5 - 6.5, tolerating 5 - 7[].
The plant develops a lignotuber - this is a woody tuber that starts to develop near the base of seedlings and can become massive in the mature plants of some species. It possesses embedded vegetative buds, allowing the plant to regenerate following crown destruction, for example by fire[].
This is one of the few eucalypts that make an attractive understorey in the better mountain forests of eastern Australia[].
There are limited prospects for planting this species except for essential oil production from provenances selected by experts[].
The tree has been grown successfully in several countries. It is a good coppicing species, so a useful provenance for essential oils could be reproduced by annual coppice cuts[]..
Eucalyptus species have not adopted a deciduous habit and continue to grow until it is too cold for them to do so. This makes them more susceptible to damage from sudden cold snaps. If temperature fluctuations are more gradual, as in a woodland for example, the plants have the opportunity to stop growing and become dormant, thus making them more cold resistant. A deep mulch around the roots to prevent the soil from freezing also helps the trees to survive cold conditions[]. Many members of this genus are remarkably adaptable however, and there can be a dramatic increase in the hardiness of subsequent generations from the seed of survivors growing in temperate zones[].

Edible Uses

None known

Medicinal

An essential oil from the leaves is used in aromatherapy[].

Agroforestry Uses:

The tree is sometimes grown to provide shelter[].

Other Uses

The fresh leaves contain from 0.3 - 3.9% essential oi (up to 6.3% dry weight)l. Quantities and content can vary very significanly within the species, but the main components are alpha-pinene (up to 80% in some forms), 1,8-cineole (up to 70%), eudesmol (up to 40%), gamma-terpinene (up to 12%), terpinen-4-ol (up to 25%)[].
Eucalypts now considered to be provenances of Eucalyptus radiata, such as 'Eucalyptus phellandra' which yields 3 - 4.5% of a pale-coloured essential oil, and Eucalyptus radiata var. australiana which yields 2.5 - 5% of an essential oil containing 70% or more of cineole, are valuable provenances. The provenances must be expertly selected[].
The essential oil obtained from the leaves and young stems is used as an ingredient in commercial cosmetic preparations as a perfume, masking agent, skin conditioner[].

The heartwood is light brown, moderately coarse-textured, generally straight-grained and moderately durable, but with many gum veins. Shrinkage on seasoning is rather high. It is used for general light construction, with select grades suitable for joinery[, , ].

Propagation

Seed - surface sow late winter/early spring in a sunny position in a greenhouse[, , ]. Species that come from high altitudes appreciate 6 - 8 weeks cold stratification at 2°c[]. Pot up the seedlings into individual pots as soon as the second set of seed leaves has developed, if left longer than this they might not move well. Plant out into their permanent positions in early summer and give them some protection from the cold in their first winter. The seed can also be sown in early summer, the young trees being planted in their final positions in late spring of the following year. The seed has a long viability[].