Common Name: Tasmanian Yellow Gum

General Information

Eucalyptus johnstonii is an evergreen tree with a heavily branched crown; it can grow 40 - 60 metres tall, though is dwarf and stunted at higher elevations. The bole is usually straight, up to 150 - 200cm in diameter, and sometimes slightly buttressed at the base[, ].
The tree is harvested from the wild for its high quality wood. It can be grown in shelterbelts to provide protection from strong winds.

Known Hazards

None known

Botanical References

Range

Australia - southeastern Tasmania.

Habitat

Usually found on badly drained sandstone; at elevationss from 600 - 2,600 metres[]. Montane forests on sites subject to some waterlogging on peaty, sandy soils[].

Properties

Other Uses Rating
Habit	Evergreen Tree
Height	50.00 m
Growth Rate	Slow
Pollinators	Bees, Insects
Cultivation Status	Wild

Cultivation Details

Eucalyptus johnstonii is native to the temperate climate of Tasmania, where it is found at elevations from 500 - 1,000 metres. Rainfall occurs mainly in the winter, with a mean annual rainfall within the range 1,000 - 2,000mm. There are generally around 50 - 90 frosts a year[]. A fairly hardy species, it tolerates long periods down to -6°c and short periods down to -9°c[]. Plants are hardy to between -15°c and -20°c according to other reports[, ].
Prefers a sunny position in a moderately fertile well-drained moisture retentive circum-neutral soil[]. Dislikes clay or chalk soils but succeeds in most other soils[]. Tolerates poor soils, especially those low in mineral elements[]. Tolerates dry soils and also drought once it is established[]. Tolerates maritime exposure, though the foliage may be burnt. Prefers a pH in the range 5.5 - 6.5, tolerating 4.5 - 7.5[].
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[].
A slow-growing species[].
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[].
This species is sometimes included as a sub-species of E. vernicosa[].
Plants are shallow-rooting and, especially in windy areas, should be planted out into their permanent positions when small to ensure that they do not suffer from wind-rock[]. They strongly resent root disturbance and should be container grown before planting out into their permanent position[].

Edible Uses

None known

Medicinal

None known

Agroforestry Uses:

Tolerates maritime exposure, though the foliage may be burnt, and it can be grown as a shelter belt tree[].
The flowers are rich in nectar and are a good bee crop[].

Other Uses

An essential oil is obtained from the leaves. Total quantity of the oil, and its composition, can vary widely from plant to plant, but we have reports that the fresh leaves contain around 0.5 - 1.8% (4.6 - 5.0% dry weight) essential oil. The main components include 1,8-cineole (62%), pinene (19%), limonene (6%), terpinene and eudesmol[].

The heartwood is pale pink-brown and of of moderately high density. Of high quality, it is easily worked and is used for joinery, cabinet work and piles [, , ].

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[].