Common Name: Sydney Peppermint

General Information

Eucalyptus piperita is an evergreen tree that can grow up to 20 metres tall[].
The tree is harvested from the wild mainly for its essential oil, which can be used medicinally. It is grown as an ornamental.

Known Hazards

None known

Botanical References

,

Range

Australia - New South Wales

Habitat

Found in most soils, especially if they are on the poor side[], it prefers sandstone soils on the cool sides of valleys and ridges; at elevations up to 1,000 metres[, ].

Properties

Medicinal Rating
Other Uses Rating
Habit	Evergreen Tree
Height	12.00 m
Growth Rate	Fast
Pollinators	Bees, Insects
Cultivation Status	Ornamental, Wild

Cultivation Details

Eucalyptus piperita is native to the warm temperate climate of eastern Australia, where it is found at elevations up to 1,000 metres. Rainfall can occur all year round or mainly in the summer, with a mean annual rainfall within the range 1,000 - 1,200mm. There are generally up to 50 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[].
Prefers a sunny position in a moderately fertile well-drained moisture retentive circum-neutral soil[]. Tolerates poor and dry soils, especially those low in mineral elements[]. Established plants are drought tolerant[]. 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[].
Trees respond well to coppicing[].
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[].
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[].
The leaves, when crushed smell similar to peppermint

Edible Uses

None known

Medicinal

Eucalyptus leaves are a traditional Aboriginal herbal remedy.
The essential oil found in the leaves is a powerful antiseptic and is used all over the world for relieving coughs and colds, sore throats and other infections[]. The essential oil is a common ingredient in many over-the-counter cold remedies[].
An essential oil obtained from the leaves is stomachic[]. It is used to treat digestive problems[].

Kino resin, obtained from the trunk, is very astringent. Diluted, it can be taken internally as an effective treatment for dysentery, working because it is not absorbed at all from the stomach and only very slowly from the intestine, and is thus able to directly treat the lower part of the intestine. It can be used as a gargle and mouthwash to treat relaxed throat, loose teeth[, ].
Applied externally as a wash, it is an effective styptic and can used to treat cuts and skin problems[].

Agroforestry Uses:

The flowers are rich in nectar and are a good bee crop[].

Other Uses

The leaves yield up to 0.8% essential oil[]. This oil is rich in piperitone, which can be used in the synthesis of the medically active menthol, though it is not known whether this is commercially feasible[]. The essential oil is an effective inhibitor of hydrochloric acid corrosion when coated over steel[].
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 can contain from 0.6 - 2.3 % essential oil. The main components include pinene, phellandrene (up to 18%), 1,8-cineole (around 25% in some forms), piperitone (40 - 50% in some forms), eudesmol (around 20% in some forms)[]

A kino resin is obtained from the trunk[]. Kino resins are rich in tannins and are very astringent. Soluble in water, they can be used medicinally; in tanning; as well as for preserving and dyeing natural fibres. When boiled in an iron pot they produce a thick, dark liquid that can be used as an ink[].
The resin oozes naturally from wounds in the trunk and can be tapped by making incisions in the bark. At first it is a thick liquid, but soon hardens upon exposure to the air and sun, typically drying to an amber-like material that consists of dark red angular fragments, rarely larger than a pea. Freshly exuded kino is more effective than kino that has been on the tree for a long while, since the soluble portion can be more or less washed out and the action of the sun can alter their chemical composition[].

Wood - hard, straight grained but liable to gum veins. It makes a good fuel[].

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[].