EUCALYPTUS TREES

Ian.
I have noticed that some people in the peninsula are growing eucalyptus trees. What do you know about them? Where do they originate from and will they grow well around here? Thanks S.N. by e-mail

Reply.
Eucalyptus trees have dotted the Australian landscape for millions of years, and today they are probably Australia’s most common trees, able to survive poor soil, dry spells, and fire. The trees look tender but they are hardy enough to have spread throughout much of the harshest land and take a central place in the lives of the forest's wildlife. Fires sweep through eucalyptus forests quite regularly, destroying everything and leaving behind charred earth. The area appears to be devastated, but the eucalyptus trees recover quickly and even thrive. Eucalyptus leaves contain oils that can actually fuel an intense fire, but the tree's thick bark protects its core from damage. In fact, eucalyptus trees are so well adapted to fire that a conflagration actually causes them to flourish. Soon after a fire dies out, chemical changes triggered by the flames' heat cause new buds to shoot out of the trees. The fire's hot winds can also help distribute eucalyptus seeds, sowing new tree colonies far and wide and eventually providing new homes for wildlife.

One of Australia's most famous residents, the sleepy koala, also depends on the eucalyptus. Koalas feed exclusively on eucalyptus leaves, later settling into the tree's crooks and branches for a nap. Even some plants depend on the tree. Fronds of mistletoe occupy the upper branches, living off the sap of its host. The clinging plant, in turn, provides food for mistletoe birds, which return the favour by spreading mistletoe seeds to other treetops in their droppings.
Humans, not surprisingly, have also learned to take advantage of the versatile eucalyptus. The fragrant oils produced by the tree are used in the mining industry to float detritus away from valuable ore, as a base in many perfumes, and in many cold medications, such as throat lozenges and chest rubs and is an antiseptic.

GROWING THE TREE
The Eucalyptus grows to an average of 20 to 30 feet tall but could reach 50 feet in a sheltered spot; so don’t put it too close to the house. Young leaves are round, grey-green, and about 1 inch in diameter and grow opposite each other on the stem. They become longer, more oval shaped with pointed ends, as they get older. The flowers are a creamy white and grow in 1-inch clusters. The bark is reddish-brown and fibrous. The Eucalyptus usually grows in sunny, dry climates but they are seen more and more in Ireland. One peculiarity about the tree is that it will shed some of its leaves in the middle of summer. The tree seems to think that it is winter, as it would be in it’s native home. The tree only looses a portion of its leaves though so it is seen more as an evergreen. The most popular tree is the “gunnii” If you are thinking of growing one in your garden then put in a sunny spot. Make sure that the soil is well drained the trees do not like sandy or chalky soils. If you want to grow it a tree then leave it to its own devices for a few years. Alternatively you could prune it back every year and maintain it as a shrub. The young leaves will be in demand for flower arrangers.

Horticultural.