Common Name: Red Ironbark

General Information

Eucalyptus sideroxylon is an evergreen tree; it can grow up to 35 metres tall. The straight, cylindrical bole can be up to 120cm in diameter[, ].
The tree yields an excellent quality wood as well as an essential oil and tannins. It is commonly harvested from the wild and has often been planted outside its native range. This is one of three species of tree that produce a much sought-after, immensely strong and durable timber known as 'Red Ironbark'[]. It grows well in Mediterranean climates and is also planted in places such as DR Congo, Ethiopia, Kenya, Uganda, Tanzania, Zambia, Zimbabwe, Madagascar and South Africa[]. Eucalyptus sideroxylon is also planted as a shade and ornamental tree, and the flowers provide bee forage[].

Known Hazards

None known

Botanical References

, ,

Range

Australia - northern Victoria, New South Wales and southeast Queensland.

Habitat

Poor shallow soils in undulating woodland[]. Usually found on poor shallow soils, including sands, gravels, ironstones and clays; frequent in gold-bearing country; at elevations up to 600 metres[].

Properties

Other Uses Rating
Habit	Evergreen Tree
Height	30.00 m
Growth Rate	Fast
Pollinators	Bees, Insects
Cultivation Status	Cultivated, Ornamental, Wild

Cultivation Details

Eucalyptus sideroxylon is native to the warm temperate and subtropical climate of inland eastern Australia, where it is found at elevations up to 600 metres. Rainfall can occur all year round or mainly in the summer, with a mean annual rainfall within the range 375 - 625mm and a dry season that can be severe of up to 6 - 8 months. The mean maximum temperature of the hottest month is 32°c or more; mean minimum temperature of the coldest month is 3 - 5°c, and there are generally around 5 - 20 frosts a year[]. It is not a very cold-hardy plant, being able to tolerate short periods with temperatures down to about -10°c when fully dormant[].
Prefers a sunny position in a moderately fertile well-drained moisture retentive circum-neutral soil[]. Tolerates poor soils, especially those low in mineral elements[]. Succeeds in most soils, including limestone[]. Tolerates dry soils and also drought once it is established[].
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[].
The tree has a thick, hard, corrugated bark[]. This species is one of the ironbark group of Eucalypts. The resin exudes into the bark then hardens making the bark very haed and difficult to cut through with primitive tools[].
A good coppicing species but difficult to debark in winter[].
Whilst most Eucalyptus species, grown in small numbers outside their native range, can be an attractive and useful addition to the landscape, certain species (including this one) are more problematic. When grown in monocultures, especially outside their native range, they can become an environmental disaster. They are voracious, especially in their use of water; they are allelopathic, inhibiting the growth of the native flora; they reduce habitats for native fauna; and encourage the worst possible attitudes to land use and conservation[].
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[].

Edible Uses

None known

Medicinal

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

An essential oil is obtained from the leaves. The oil is thin, limpid, very pale yellow ; the taste and smell are like that of
the oil of Eucalyptus oleosa. A yield of about 1% has been obtained, but this amount should be taken as approximate only, as the leaves had lost some part of their oil through being heated in transit[]. The leaf oil has been produced commercially in South Africa, where it was used as a flotation agent in the mining industry[].

The bark contains 21.94% tannic acid. Of lower quality, it imparts a dark coloration, and also seems to impair the tanning process. Sails and nets tanned with it become dark-coloured and hard[].
The dried leaves yield 9.5% tannic acid[].

The bark contains up to 23% kino resin. 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[].

The dark red wood has a close, interlocked grain and fine texture. It is very heavy, dense, strong, stiff, hard, very durable and resistant to termite attack, with a density of 1,060 kg/m3. It is used for construction, bridge piles, railway sleepers, posts and other purposes where great strength and durability are required[, , , ].
The wood makes an excellentr fuel and is used for making charcoal[, ].

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[].