Eucalyptus camaldulensis (River red gum) is a tree which grows to a height of 30 m and a width of 20 m. It has a fast growth rate. It has a hardiness rating of 9. The flowers from this plant are hermaphrodite (has both male and female organs) and they are pollinated by bees.
Australia - in all mainland states.
Eucalyptus camaldulensis Growing Guide
Ideal Soil and Planting Location for River Red Gum
River red gum will grow in light (sandy), medium (loamy), hard (clay) soil. River red gum well-draining soils. River red gum should not be planted in shady areas. Sandy to heavy soils, usually along the banks of streams.
River Red Gum Cultivation Details
Prefers a sunny position in a moderately fertile well-drained moisture retentive circum-neutral soil. Succeeds in most soils, tolerating poor and dry soils, especially those low in mineral elements. A drought resistant tree once established, it is slightly salt tolerant, and can also withstand periodic inundation.
A very fast growing tree. Plants tolerate an annual precipitation of 103 to 206 cm and an annual temperature range of 18.0 to 26.6°C. It is reported to grow in areas with only 20 cm rainfall, but the lower limit for commercial plantations is 40 cm.
Some provenances tolerate many different soil conditions such as high calcium, high salt and periodic water-logging. The mean maximum temperature of the warmest month where it grows well is 29°C. The dry season lasts 4-8 months or more and may be severe.
River Red Gum Frost Resistance
Fairly frost resistant, plants survive temperatures down to at least -7°c in Australian gardens. This figure is not directly relatable to British gardens, however, because of our cooler summers and colder, wetter winters. It could be worthwhile giving this species a try in the milder areas of the country.
Some provenances can tolerate temperatures down to about -5°C and up to 20 frosts per year. 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. The members of this genus are remarkably adaptable; however, there can be a dramatic increase in the hardiness of subsequent generations from the seed of survivors growing in temperate zones.
Trees are liable to shed branches, especially in hot weather. This is said to be the most widely distributed eucalyptus tree in Australia, ranging over 23° lat. in most of arid and semiarid Australia but not the humid eastern and south-western coasts.
It is regarded as one of the most widely planted eucalypts in the world with more than 500,000 ha planted. It is planted in Europe, especially in Italy, as a timber crop, for soil stabilisation and as an antimalarial measure.
Some provenances coppice well for six or more rotations, on good sites, plantations are managed on coppice rotations of 7 - 10 years. Eucalyptus monocultures are an environmental disaster, they are voracious, allelopathic and encourage the worst possible attitudes to land use and conservation.
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.
Survivalists in Australia and elsewhere might learn how the aborigines obtained water from the superficial roots, usually those ca 3 cm in diameter. The roots were excavated or lifted to the soil surface.
Then the root was cut into segments ca 45 cm long, debarked, held vertically, and blown into, the water then draining into the receptacle provided. The flowers are rich in nectar and are a good bee crop.
Eucalyptus camaldulensis Medicinal Uses*
* See disclaimer
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. The plant is an aromatic, astringent, tonic herb that sticks to the teeth and turns the saliva red.
The report says that the leaves, essential oil and oleo-resin are used, but does not specify which properties apply to the different parts of the plant. The leaves and the oil will have very similar properties, the oil being much stronger in its effect since it is distilled from the leaves.
Detailed below is how the oleo-resin and oil are commonly used in other species. The essential oil obtained from various species of eucalyptus is a very powerful antiseptic, especially when it is old, because ozone is formed in it on exposure to air.
It has a decided disinfectant action, destroying the lower forms of life. The oil can be used externally, applied to cuts, skin infections etc, it can also be inhaled for treating blocked nasal passages, it can be gargled for sore throat and can also be taken internally for a wide range of complaints.
Some caution is advised, however, because like all essential oils, it can have a deleterious effect on the body in larger doses. An oleo- resin is exuded from the tree. It can also be obtained from the tree by making incisions in the trunk.
This resin contains tannin and is powerfully astringent, it is used internally in the treatment of diarrhoea and bladder inflammation, externally it is applied to cuts etc. Treats throat ailments.
Eucalyptus camaldulensis Propagation
Seed - surface sow February/March 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 June, the young trees being planted in their final positions in late spring of the following year. The seed has a long viability.
Red River Gum Eucalyptus Known Hazards
Citronellal, an essential oil found in most Eucalyptus species, is reported to be mutagenic when used in isolation. In large doses, oil of eucalyptus, like so many essential oils, has caused fatalities from intestinal irritation.
Death is reported from ingestion of 4-24 ml of essential oils, but recoveries are also reported for the same amount. Symptoms include gastroenteric burning and irritation, nausea, vomiting, diarrhoea, oxygen deficiency, weakness, dizziness, stupor, difficult respiration, delirium, paralysis, convulsions, and death, usually due to respiratory failure.
Other Uses for Red River Gum
A gum is obtained from the plant. It is used medicinally and in tanning. The leaves contain 0.1 - 0.4% essential oil, 77% of which is cineol There is some cuminal, phellandrene, aromadendrene (or aromadendrin), and some valeraldehyde, geraniol, cymene, and phellandral.
The leaves contain 5 - 11% tannin. The kino contains 45% kinotannic acid as well as kino red, a glycoside, catechol, and pyrocatechol. The leaves and fruits test positive for flavonoids and sterols. The bark contains 2.5 - 16% tannin, the wood 2 - 14%, and the kino 46.2 - 76.7%.
A fast growing tree with wide-ranging roots, it can be planted in soil stabilisation schemes and can also be planted in marshy land where it will help in draining the land, thereby destroying a potential breeding site for mosquitoes.
It is planted in S. Italy for this purpose. The wood, durable, easy to saw, yet resistant to termites, is widely used in Australia for strong durable construction, interior finish, flooring, cabinetry, furniture, fence posts, cross-ties, sometimes pulpwood.
Australian aborigines made canoes from the bark. According to NAS (1980a), annual wood yields are around 20-25 m3/ha in Argentina, 30 m3 from Israel, 17-20 from Turkey in the first rotation, and 25-30 in subsequent coppice rotations. On poor arid sites yields are only 2-11 m3 on 14 or 15 year rotations.
- Trees and Shrubs Hardy in Great Britain. Vol 1 - 4 and Supplement. Author: Bean. W.
- Eucalypts. (2 volumes.) Author: Kelly. S.
- The New RHS Dictionary of Gardening. 1992. Author: Huxley. A.