The eucalyptus is an evergreen tree originating in Australia. There are more than 600 species of eucalyptus including Eucalyptus globulus, Eucalyptus robusta and Saligna eucalyptus. Some grow to be mere shrubs while others become giant trees. All thrive in warm, tropical and subtropical climates. They have been introduced to places such as Florida and California where they thrive. Eucalyptus trees are known for the gum or thick sap they exude and many fall into either the red gum or blue gum types.
Originating in Australia, most eucalyptus trees are found in coastal and on watersheds. Along rivers and streams and in lagoons and swamps the tree thrives in areas where flooding occurs as well in mountainous areas. A common climate factor all eucalyptus trees share is they require rainfall of 50 or more inches a year and they cannot handle severe frosts or deep freezes.
Eucalyptus Growth Stages
The eucalyptus passes through four distinct stages of growth. The first stage is the seedling which is generally about the first year. The juvenile stage or sapling stage occurs next and ends when the diameter reaches 4 inches at breast height or about 4 to 5 feet tall. During this phase, which lasta until the tree is roughly 18 months old, the juvenile leaves are powdery silver to gray and oval shaped. The intermediate stage follows and then the mature or adult stage. Adult leaves are green, leathery and are 4 to 12 inches long. During the intermediate stage, the tree will bear both types of leaves. Maturity is reached when the tree has lost all the juvenile leaves.
Eucalyptus Tree Facts
Eucalyptus globulus can reach heights of 375 feet and can live for 500 to 1,000 years. During its initial 20 years it can climb to heights of 175 feet. Roots spread outward as much as 100 feet, competing with neighboring vegetation as well as downward to depths of 45 feet. Other eucalyptus trees reach 200 feet. They are not generally destroyed by fire and often a fire has a rejuvenating effect on a stand eucalyptus trees.
The eucalyptus tree produces oil that is used for several medical purposes. During World War II it was used to treat meningitis and influenza. The oils have been made into ointments and used to treat fungal infections and to clean urinary catheters. It is used today as an expectorant, antibiotic and in deodorant. The oil of Eucalyptus globules species make the leaves unacceptable to the koala bear, which dines exclusively on eucalyptus leaves with a lower oil content.
Uses for the Wood
Eucalyptus trees are in demand by the wood pulp industry because of their rapid growth. Achieving 60 percent of their height in the first 10 years of life, the eucalyptus can be harvested more quickly than most other pulp wood species. It is a dense wood with little graining, making it desirable for hardwood projects. It is used for poles and posts and as mulch. Its density and longevity make it ideal for construction of homes and it has been used to build railroad cars.