Common Name: Narrow-leaved Tea Tree

General Information

Melaleuca alternifolia is an evergreen shrub growing up to 7 metres tall[].
The plant is the source of a very widely used essential oil that has been shown to be strongly antiseptic. It is exported in large quantities from Australia where the plant is sometimes cultivated[].

Known Hazards

None known

Botanical References

Range

Australia - New South Wales, Queensland.

Habitat

Often in dense, impenetrable, thickets, usually in swamps by the coast, and at elevations up to 300 metres[].

Properties

Medicinal Rating
Other Uses Rating
Habit	Evergreen Shrub
Height	6.00 m
Pollinators	Insects
Cultivation Status	Cultivated, Ornamental, Wild

Cultivation Details

Melaleuca alternifolia is a plant of the warm, moist subtropics of eastern Australia, where it can be found at elevations up to 300 metres, the plant is also sometimes cultivated as an ornament in tropical areas[]. It is found in frost-free areas where daytime temperatures can range from 17 - 19°c up to 27 - 31°c, and the mean annual rainfall is 1,000 - 1,600mm[]. Although not very cold hardy, the plant can tolerate short periods with temperatures down to at least -7°c when dormant, so long as the summers have been sufficiently hot enough to thoroughly ripen the wood. It can therefore be cultivated in areas such as the Mediterranean where hot summers are followed by mild winters[, ].
Requires a fertile, well-drained moisture retentive lime-free soil in full sun[]. Prefers a soil that does not contain much nitrogen[]. Plants are shade tolerant and succeed in most soils and aspects except dry conditions when they are grown in Australian gardens[]. Plants can tolerate a pH from 4.5 - 7[].
Harvesting of the leafy twigs for their essential oil starts 15 - 18 months after establishment of the plants, and subsequently at 12 - 15 month intervals[]. The shoots are cut when less than 2cm in diameter and at 5 - 10cm above soil level[].
Annual yield of shoots is about 8 - 10 tonnes per hectare, the shoots having an oil content of 1 - 2%[].
Seed takes about 12 months to develop on the plant, the woody seed capsules persist for 3 or more years[].
Any pruning is best done after the plants have flowered with the intention of maintaining a compact habit[].
Hybridizes freely with other members of this genus[].
Plants in this genus are notably resistant to honey fungus[].

Edible Uses

None known

Medicinal

Tea tree, and in particular its essential oil, is one of the most important natural antiseptics and it merits a place in every medicine chest[]. It is useful for treating stings, burns, wounds and skin infections of all kinds[].

An essential oil obtained from the leaves and twigs is strongly antiseptic, diaphoretic and expectorant[, , ]. It stimulates the immune system and is effective against a broad range of bacterial and fungal infections[]. Internally, it is used in the treatment of chronic and some acute infections, notably cystitis, glandular fever and chronic fatigue syndrome[]. It is used externally in the treatment of thrush, vaginal infections, acne, athlete's foot, verrucae, warts, insect bites, cold sores and nits[]. It is applied neat to verrucae, warts and nits, but is diluted with a carrier oil such as almond for other uses[].
The oil is non-irritant[]. Another report says that high quality oils contain about 40% terpinen-4-ol, which is well tolerated by the skin and 5% cineol which is irritant. However, in poor quality oils the levels of cineol can exceed 10% and in some cases up to 65%[].
The essential oil is used in aromatherapy. Its keyword is 'Antiseptic'[].

Other Uses

An essential oil is obtained from the leaves[, ]. It is strongly germicidal and is also used in dentistry, deodorants, soaps, mouthwashes etc[, ]. The oil is also of interest in the perfume industry, as it blends well with other oils while contributing its own distinctive note to soaps, deodorants and colognes[].

Wood - very durable in wet conditions and in damp ground[].

Propagation

Seed - surface sow in spring or autumn onto a pot of permanently moist soil in a warm greenhouse. Emmerse in 5cm of water and do not water from overhead. Grow on until the seedlings are 0.5cm tall then remove from the water and pot up a week later. Seedlings are liable to damp off when grown this way, sowing the seed thinly, good ventilation and hygiene are essential for success[]. Grow the plants on for at least their first winter in a greenhouse and then plant them out in late spring or early summer, after the last expected frosts. Consider giving the plants some protection from the cold for their first few winters outdoors.
Cuttings of half-ripe lateral shoots with a heel, mid summer in a frame[].