This Eucalyptus, or Cider Gum, is an attractive tree which is non- native, originating in Tasmania. Of the over 700 species of Eucalyptus worldwide, Gunnii, being hardy, is the most popular type in this country - unfortunately, as it is very fast growing, and extremely dangerous to building foundations: it grows in only around 10-20 years to the height of some 14 metres (45 ft.11 ins.) or more, with a canopy of around 10 metres (32ft), and a root spread of 1.5 times its height. Other hardy varieties include E. dalrympleana ( Mountain Gum), E. pauciflora (Snow Gum), but all need space to themselves. At Kew in 1774 the first introduction of E. obliqua (Stringy Bark) took place from seed collected on Captain Cook’s antipodean explorations.
Due to its rampant growth and invasiveness, Eucalyptus has become the subject of many an acrimonious law suit between neighbours, subsidence being commonly caused by this tree, which is unsuitable within 18 metres (59ft) of any building, and especially drains, where legal liability for damage rests with the tree owners. Sadly many urban nurseries sell these trees without any warnings that they are only suitably propagated in very large open spaces. In their native habitats, Eucalypts have often been used as a way to drain swamps.
Surprisingly Eucalypts belong to the wonderful Myrtle family, and are therefore evergreen, with beautiful round young blue-green leaves, very dear to flower arrangers, which mature into lovely sickle-shaped more grey-green, leaves, which tend to hang down, thus designed to withstand scorching sun. Curiously the juvenile leaves are opposite, whereas the mature leaves are alternate. The bark sometimes resembles a stunning abstract painting, with its peeling cream and brown bark.
Eucalypts take their name from the Greek ‘Eu’ meaning ‘well’ and ‘calypt’ meaning ‘hidden’, the latter referring to the nature of the flower which first forms hidden in the operculum, or cap on the flower bud. Over the years the Eucalyptus citronellal oil has been used for its seeming beneficial qualities, such as in inhalations, though it is also capable of serious toxicity and even death. Interestingly the tree itself, has the effect of repelling some insects and certain wild life, and little will grow beneath them.
This tree can be pruned regularly and even kept as a relatively low bush, with very keen maintenance, but pruning stimulates growth, and thus can make the tree thirstier and therefore even more invasive.
Eucalyptus is thus wholly unsuitable for small gardens anywhere, but its beauty is clear, so one hopes that the message of caution will spread that they should really only be for forests, deserts, mountains, swamps, and some large parks!
Mary Poole-Wilson Trees Committee
