Eucalyptus are evergreen trees or large shrubs, often fast-growing, some with attractive bark, most with aromatic foliage, and clusters of small, white, yellow or red flowers.
I read that somewhere, and it’s a pretty good description of what we normally refer to as a gum tree. In their home of Australia, there are more than 700 varieties of eucalyptus, many with wonderful names – woollybutt, messmate, stringybark and candlebark, which tells you just what can happen when things get hot. Gum trees burn with a vengeance.
Thankfully, we don’t often get bush fires in the UK, so despite recent problems with disease, eucalyptus have become quite popular as specimen trees, particularly for their lovely young foliage and peeling bark.
E gunnii is probably the most numerous. In its native Oz, it is a large evergreen tree with peeling cream and brown bark. Juvenile foliage is bright glaucous-blue and rounded, while the older leaves are sickle-shaped and a duller grey-green. Which is why many people opt to prune their gum trees annually – not only does it keep the trees a manageable size, but it also encourages the production of those infinitely prettier young leaves.
E gunnii likes full sun, but it’s not bothered how it gets it – it can grow well in north-facing, east-facing, south-facing or west-facing sites, just as long as it has some shelter from strong winds. Grow it in a slightly acidic, moist soil which is well-drained, and it should be happy.
Pruning gum trees can be as difficult or as easy as you make it. Some gardeners prune to train; others prune to contain. But one thing is pretty much the same – young eucalyptus normally need some formative pruning to grow into well-shaped mature trees.
Some species can also be trained into multi-stemmed bushes, either by coppicing an established tree, or by training two-year-old trees as multi-stemmed shrubs from the beginning of their life, but few people can be bothered to adopt such a regime.
If you have a small garden, consider coppicing or pollarding established trees. Coppicing creates a multi-stemmed bush, by chopping back the stems to the ground every year or every few years. It is particularly good for E gunnii, encouraging new stems and the growth of juvenile leaves.
The work is best carried out in February or March before the tree begins to wake up for another year of growth.