Eucalyptus is an enormous and fascinating genus. It comprises over 700 species and accounts for more than two-thirds of Australia s vegetation. However, their growing zone is not limited to Australia -- they can survive in cooler areas. There are many reasons to plant a eucalyptus -- to begin with, they help to control aphids and other insects; most of them will grow rapidly, even in poor soil (12' per year is not out of the question); and most of them are very attractive -- eucalyptus trees have a beauty all their own. Eucalyptus foliage, which shows incredible variety, is excellent in floral arrangements.
Unless it is to be grown as a pot plant for its entire life, a eucalyptus seedling must be planted as soon as possible, before too many roots reach the edges and bottom of its pot. Eucalyptus ought to be planted outside when they are between 8 - 14 inches in height.