Life

The Casual Gardener: You’ll love a eucalyptus

With eye-catching white flowers, attractive bark and year-round fragrant foliage, eucalyptus are excellent value

Be wary as eucalyptus rank among the world's tallest and fastest-growing trees
Be wary as eucalyptus rank among the world's tallest and fastest-growing trees Be wary as eucalyptus rank among the world's tallest and fastest-growing trees

I QUITE like the idea of adopting a koala. They seem pretty benign creatures, friendly and completely unfazed, even in the face of bushfire adversity.

Containing the adopted koala(s) in the same manner my two dogs are kept within the bounds of the garden would be challenging though because they are arboreal (live in the trees) marsupials who could easily scale the fence or wall.

I reckon the solution is to plant some eucalyptus trees, as the koala’s diet consists solely of eucalyptus leaves. It’s said that because it eats up to 3lbs of eucalyptus leaves each day, it smells like eucalyptus. As someone who shares a house with a springer spaniel that exudes a perennial damp, earthy odour, this can be regarded as yet another positive koala attribute.

But be warned before you rush out and start planting up your own koala sanctuary, eucalyptus grow very quickly – up to a meter a year – and in some cases very big.

Commonly known as the gum tree in its native Australia, where they outnumber other trees by around three-to-one, Eucalyptus regnans is the tallest of all flowering plants, with the tallest measured living specimen, named Centurion, standing just over 100 metres (330 feet) tall in Tasmania.

The key is to buy one of the smaller varieties or to keep the tree in check using pruning techniques like coppicing and pollarding.

If pruned properly in its early years, the eucalyptus will develop into a well-shaped mature tree. Also, if you have a tree that’s getting out of control you can coppice by chopping back the stems every few years to create a multi-stemmed tree. This technique is particularly effective with Eucalyptus gunnii, E. globulus, E. dalrympleana and E. pauciflora as it not only encourages new stems each year, but also juvenile leaves, which tend to more attractive than their mature counterparts.

Pollarding is a pruning technique that is employed once the tree reaches a certain height and usually requires the services of a tree surgeon. Pollarding is suitable for E. dalrympleana and E. pauciflora.

Despite originating in the Tropics, the high-altitude provenance of the eucalyptus means it’s pretty hardy and can easily withstand sub-zero temperatures. They’re also an unfussy tree, content in a wide range of soil types, as long as well-drained, and not particularly prone to pests and diseases. Eucalyptus can also recover when left charred by a bushfire and while such damage isn’t as yet a major concern for Irish gardeners, it is illustrative of the tree’s resilience.

Like any tree, be wary of planting them too close to buildings. Just ensure you give your tree a good sunny spot and enough room for its canopy to develop evenly. It’s also recommended buying a young sapling, little more than a one meter tall, as eucalyptus are prone to windrock and don’t much like their roots constrained, making them unsuitable as containerised trees. No need to stake either as it’s necessary to develop strong roots that will help anchor it.

Recommended varieties for the best bark are E. pauciflora subsp. Niphophila', which has a bark that flakes away to leave cream, green and grey patches; E, archeri (Alpine Cider Gum) for smooth grey-green, pinkish white or brown bark; and Eucalyptus stellulata ‘Black Sally’ with rough brown to black bark on the lower trunk and smooth, olive green and white and the upper.

Now sit back and wait for the koalas to arrive.