The Australian aborigines traditionally used various herbal remedies made from different parts of the Eucalyptus to treat fevers and all kinds of infections. These days, remedies made from the eucalyptus are used by many people all over the world for the treatment of these types of complaints. The potent anti-septic and anti-viral power of the eucalyptus makes it very helpful to treat colds, flu, and it is often used as a gargle to treat sore throats. The remedies made from the eucalyptus are effective in the treatment of chest infections of all kinds as the plant has strong expectorant action - disorders like bronchitis and pneumonia are often treated using this herbal eucalyptus remedy. The essential oil of the eucalyptus is diluted and then used on the skin as a form of herbal chest or sinus rub, this oil induces a warming and mildly anesthetic effect on the skin. The oil helps in relieving respiratory infections and complaints of all kinds. A similar effect can be induced by the use of a eucalyptus infusion or tincture as an herbal gargle to treat soreness in the throat. The essential oil can also be used in the diluted form to bring relief from the symptoms of rheumatic joints, symptoms like sudden aching pains and stiffness. The diluted essential oil is also useful in the treatment and alleviation of the symptoms of neuralgia, and to treat some kinds of skin infections cause by bacterial pathogens.
The eucalyptus is an indigenous Australian species, originally it was found only there. Due to the great popularity of the eucalyptus as a quick growth tree, it is now extensively cultivated in plantations around the world in countries that have a tropical, sub-tropical or temperate climatic regime. Eucalyptus trees are quick growing hardy species, however, it has been increasingly realized that planting the eucalyptus plants without planning can bring great ecological disruption and environmental problems to any area. One of the primary reasons is that these trees often absorb huge volumes of water from the ground and this can prevent the normal growth of native plant species - often endangering the local plant community. However, the water absorption capability of the eucalyptus species is considered very beneficial in some cases, especially when trees are planted to help dry up marshy areas - thus lowering the risk of malaria in an area. The leaves of cultivated trees are harvested and subjected to distillation to obtain the essential oil or they are dried and used for other purposes. In cultivation, the ideal site to grow eucalyptus is in sites that have a good exposure to sunlight. The tree grows best in soils that are moderately fertile and are well drained. Eucalyptus also prefers moisture retentive and circum-neutral soils and gives optimal growth in such soils. However, as already mentioned the eucalyptus is a hardy plant and can easily grow with success in most soil types. It is a strong plant and can tolerate even poor and very dry soils. The tree is tolerant of even those soils that are particularly low in essential mineral elements required by most other plant species. One eucalyptus has been grown on a site, the established mature trees become very tolerant to drought and prolonged dry periods. When planting the eucalyptus, it is best to avoid planting in frost pockets or along windy sites. Growing eucalyptus plants usually need a sheltered position; the young eucalyptus plants may not be able to tolerate extreme cold temperatures and will also not grow well if exposed to winds that are dry or desiccating during the crucial early growth stage. Eucalyptus plants are tolerant of moderate rainfall and are tolerate annual precipitation from 80 to about 160cm. The species also tolerates fluctuations in annual temperature ranging from 16 to 20�C. As the eucalyptus is a sub-tropical species, it does not possess the deciduous habit of stopping growth in cold weather and trees will continue to grow until it turns too cold for any growth to occur. This factor makes the eucalyptus plants vulnerable to physical and tissue damage from the appearance of sudden cold conditions and frosts. Eucalyptus trees resist the cold better, when the fluctuation in the temperature is much more gradual such as in woodlands and sub-temperate areas, often stopping growth and becoming dormant - eucalyptus plants grown in such conditions or areas are much more cold resistant than plants grown in temperate or colder regions. The eucalyptus trees also survive much better and grow at an optimal rate if provided with a deep mulch in the site around the roots - this mulching prevents the freezing of the soil and aids the resistance of the trees to cold weather. The Genus Eucalyptus is nevertheless one of the most adaptable plant genuses around and the trees are remarkably hardy in all kinds of weather conditions. The hardiness of each generation can undergo a dramatic as seeds from subsequent generations of plants grown in the temperate zones are planted - the tree adapts to the local conditions in a few generations. Among all the different eucalyptus sub-species, the "Tasmanian blue gum" with a total number covering about 800,000 ha in dozens of countries around the world is considered to the most extensively planted sub-species of eucalyptus. The Tasmanian blue gum is the eucalyptus species of choice in S. Europe and can commonly be seen there, particularly in countries such as Italy, Spain and Portugal. This sub-species of eucalyptus is used as a source form commercial timber, as a tree for soil stabilization in degraded lands and as a source of the essential eucalyptus oil found in the leaf extract. Eucalyptus trees are also extensively planted in bogs and marshy areas to help lower the wetness of the land in land reclamation projects or to rid such areas of breeding mosquitoes - the high transpiration rate of eucalyptus plants is the reason for their efficiency in clearing excess water from bogs and marshes. Eucalyptus plants are shallow rooting during the early growth periods and have to be planted at the permanent sites while they are small to protect them from the danger of high winds. Eucalyptus saplings do not tolerate disturbance to the root system very well and are best grown in containers initially before they are taken for planting at permanent sites. Eucalyptus trees are also favored by apiarist as the nectar rich flowers are a good source of nectar for bees. The typical balsamic eucalyptus aroma is given off by leaves when they are slightly bruised - a stand of eucalyptus trees can be identified by the presence of this peculiar aromatic smell. Eucalyptus trees are propagated using stored seeds. The seeds are sown on the soil surface either in February or March, usually in seedbeds within greenhouse - sites with good exposure to incoming sunlight is preferred. The best method to grow seedlings of sub-species that are from high altitudes is to subject them to cold stratification for six or eight weeks. As soon as the second sets of seed leaves appear, the seedlings are placed into individual pots - this is done because, it becomes difficult to successfully move or transplant the seedlings at a later stage. Early in the summer, seedlings are planted out into the permanent positions and at this stage, usually given them some protection from the cold during the winter of the first year of growth. Eucalyptus seeds are often sown in June as well, in such a case, the young trees are only planted at the permanent site late in the spring of the next year. Eucalyptus seeds are viable for long periods of time and can be stored for years on end.
There have been numerous and extensive research into the essential oil of the eucalyptus in the last half century. The essential oil has been shown to possess a distinct and potent antiseptic action as well as a power to dilate the bronchioles and respiratory passages in the pulmonary system. The main constituent of the oil is a compound called cineole, however, the potency of cineole when used alone is weaker compared to the whole essential oil - other compounds in the oil are also responsible for the beneficial effects in addition to the cineole.
The volatile oil contains about 70% eucalyptol (1, 8-cineole), as well as pinene, limonene, alpha-terpineol, and linalool. While it is similar to the oils of related species, this oil appears to be better tolerated by the skin.