Common name: Red Ironbark

Red Ironbark is a eucalyptus species from inland eastern Australia, occurring in woodland pockets across warm-temperate and subtropical regions. A valuable tree, it yields timber, essential oil and nectar for honey production.

It may reach up to 30 m (98 ft) in its natural habitat, though it is more commonly 15 to 20 m (50 to 65 ft) tall, and it grows slowly to moderately fast.

The trunk shape varies with growing conditions, from crooked to straight, and is usually branch-free for up to half the tree's height. Branching starts close to the ground on young trees, and lower branches self-prune as the tree grows, forming a compact, irregular crown on older trees. The bark is dark red-brown to near-black, thick, tough, and deeply furrowed.

Leaves are lance-shaped, up to 12 cm (4.7 in.) long, grey-green and remain on the tree in all seasons. They have a camphor-like aroma when crushed.

The flowers are typical of Eucalyptus species, with long filaments, commonly white though occasionally red or pink, depending on the variety. They bloom in the subtropical parts of its range from winter to spring and in loose clusters of three to seven. Fertilised flowers develop into small goblet-shaped seed capsules that turn red-brown when mature, with many small, egg-shaped seeds inside.

Bendigo Botanic Gardens, Victoria, Australia

Material uses

​Essential oil - The leaves yield a reddish-yellow cineole-type Eucalyptus oil, extracted by steam distillation, though in small amounts of around 0.75% by weight. Because of their low oil yield, the leaves are usually only harvested when mixed with the leaves of high oil-yielding Eucalyptus species, such as those of the Blue mallee (Eucalyptus polybractea), a species with which it shares an overlapping distribution. The oil is used mostly for medicinal purposes, including as an ingredient in balms, ointments, liniments (salves), and oral hygiene products, and more generally in pharmaceutical, personal care, and pest insect control products.

​Stain removal - Eucalyptus oil has also proven a good stain remover, effective at removing grease, glue, and dried stains from both skin and clothing.

​Natural disinfectant - It is also used in cleaning and disinfecting products,

Anti-mildew agent -  ... also against mould and mildew,

​Natural fragrance - ...and as a natural fragrance in perfumery.

Hardwood - Red Ironbark is a heavy hardwood, averaging 950 kg per cubic meter (59 lb per cubic ft). 

Decay- and rot-resistant wood - It also has high natural resistance to rot, decay, and termites, making it a durable hardwood suitable for indoor and outdoor construction.

Timber and lumber - The heartwood is an attractive reddish-brown, and well-formed logs are sawn into planks for light construction,

​Light construction - ...such as picket fencing and beams,

Flooring and decking - ...flooring and decking,

Furniture and cabinets - ...and for outdoor furniture.

Crossties or sleepers - Logs are also cut into crossties or railway sleepers,

Heavy construction - ...and for parts used in constructing bridges and piers.

Poles and posts - Small-diameter lengths are cut for poles and posts,

Firewood - ...as well as firewood. Because the tree coppices well (re-grows after being cut back to ground level), it can be grown more widely for fuelwood, particularly in dry climates.

Charcoal - The same coppiced wood is also made into charcoal.

Cut-foliage - The grey-green foliage is sometimes used in floral arrangements.

Environmental uses

Wildlife support - The nectar-rich flowers sustain wildlife in its natural range, most notably the endangered Regent Honeyeater, a small bird of the Australian outback with striking yellow-and-black plumage.

Flowering ornamental - Pink- and red-flowering forms are cultivated as ornamentals in Australia and other countries, 

Street tree - ...mainly as street trees.

Bee forage - The flowers also produce significant quantities of nectar, and it is considered a major honey tree in Queensland and New South Wales, in its native Australia, and in the Transvaal in South Africa, where it is introduced. However, not enough pollen is produced to sustain brood-rearing honeybees, so a separate pollen source is needed to maintain and build bee colonies for honey production.

Edible uses

Honey - The honey is extra light to light amber in colour, has a mild flavour and good body, and granulates quickly, resulting in a fine grain or crystal.

Health uses

Aromatherapy oil - The essential oil is also used in aromatherapy products.

Climate

Grows naturally in dry to sub-humid warm temperate and subtropical climates, generally areas with annual lows of 6 to 16°C, annual highs of 19 to 32°C, annual rainfall of 400 to 1300 mm and a dry season of 10 months or less. It develops best, however, in areas with annual rainfall of 700 mm or more.

Growing

New plants are usually started from seed, which germinates readily and remains viable for several years under cold, dry, airtight conditions.

It performs best on free-draining clay loam, loam, sandy loam, and loamy sand soils that are slightly acidic to moderately alkaline, generally with a pH of 6.5 to 8.0, and in full sun.

Problem features

The seeds are small, though it is unclear how easily they disperse. It is recorded as an invasive species in South Africa. Still, the Hawaii Pacific Weed Risk Assessment (HPWRA) project assesses it as a low weed risk for Hawaii.

A minimum planting distance of 4 m (13 ft) from underground pipes is recommended.

Prolonged skin contact with Eucalyptus essential oil may cause burning dermatitis and blisters in some people. Ingesting large amounts can be poisonous.

Books

• Arctander, S. 1960, Perfume and flavor materials of natural origin, Elizabeth, New Jersey

• Blake, S. T. & Roff, C. 1987, The honey flora of Queensland, 3rd ed., Queensland Department of Primary Industries (QLD DPI), Brisbane

• Boland D.J., Brophy J.J. & House A. P. N. 1991, Eucalyptus leaf oils, use, chemistry, distillation and marketing, Australian Centre for International Agricultural Research (ACIAR) & Commonwealth Scientific Industrial Research(CSIRO), Inkata Press, Melbourne

• Boland, D. & Brooker, I. & McDonald, M. W. 2006, Forest trees of Australia, 5th ed., CSIRO Publishing (Ensis), Melbourne

• C.A.B. International 2013, The CABI encyclopedia of forest trees, CABI Publishing, Wallingford, Oxfordshire

• Clarke, B. & McLeod, I. & Vercoe, T. 2009, Trees for farm Forestry : 22 Promising Species, Rural Industries Research and Development Corporation (RIRDC), Wagga Wagga, New South Wales

• Crane, E., Walker, P. & Day, R. 1984, Directory of important world honey sources, International Bee Research Association, London, United Kingdom

• Cribb, A. B. & Cribb, J. W. 1982, Useful wild plants in Australia, William Collins, Sydney

• Culbreth, D. M. R. 1927, A manual of materia medica and pharmacology : comprising the organic and inorganic drugs which are or have been recognized by the United States pharmacopeia, 7th ed., Febiger, Philadelphia

• Editors of Sunset Magazine 2012, The New Western Garden Book: The Ultimate Gardening Guide, 9th edition, Sunset Publishing Corporation, California

• F. R. Beuhne 1922, Honey flora of Victoria, Melbourne Albert J. Mullett, Govt. printer

• Guenther, E. & Althausen, D. 1948 to 1952, The essential oils (6 volumes), Van Nostrand Publishing, New York

• Hall, N. 1972, The use of trees and shrubs in the dry country of Australia, Australian Government Publishing Service, Canberra, Australian Capital Territory

• Holliday, I. 2002, A field guide to Australian trees, 3rd revised editon, New Holland Publishers, Frenchs Forest, New South Wales

• Leech, M. 2013, Bee Friendly: A planting guide for European honeybees and Australian native pollinators, Rural Industries Research and Development Corporation (RIRDC), Canberra, Australian Capital Territory

• Little, E. L. & Skolmen, R. G. 1989, Common forest trees of Hawaii (native and introduced), Agricultuural Handbook No. 679, Forest Service, U.S. Department of Agriculture, Washington, D.C.

• Nicolle, D. (2016). Taller Eucalypts for Planting in Australia: Their Selection, Cultivation and Management. Dr Dean Nicolle, Adelaide.

• Perry, B. 2010, Landscape plants for California gardens: an illustrated reference of plants for California landscapes, Land Design Publishing, Claremont, California

• Randall, R. P. 2002, A global compendium of weeds, R.G. and F.J. Richardson Press, Melbourne

• Scheffer, T. C & Morrell, J. J. 1998, Natural durability of wood : a worldwide checklist of species, Forest Research Laboratory, Oregon State University, Corvallis, Oregon

• Streets, R. J. & Troup, R. S. 1962, Exotic forest trees in the British Commonwealth, Oxford University Press, Oxford, England

• Webb, D. B. 1984, A Guide to species selection for tropical and sub-tropical plantations, 2nd ed., Unit of Tropical Silviculture, Commonwealth Forestry Institute, University of Oxford, Oxfordshire

• Weiss, E. A. 1997, Essential oil crops, CABI Publishing, Wallingford, Oxfordshire