Without a doubt, my favourite tree of all time would be Angophora costata, sometimes known as the Sydney redgum because of its beautiful orange-red bark. This tree is a real icon of the Sydney sandstone country, where it can often be seen prising open big chunks of sandstone to get its roots into the side of the hill to provide an anchor point. That those soils are so poor and impoverished means an incredibly slow growth rate for this tree which tends to lend itself to the development of a beautiful, gnarly habit where the branches criss-cross each other. Indeed, I’ve occasionally seen trees where the branches on the same tree have rubbed together and formed a natural graft union – quite a remarkable sight.
So it’s a signature tree of Sydney sandstone country and, about December, one of the great ornamental features of the tree becomes evident as the smooth, rusty-coloured bark starts to shed, revealing amazing lighter-coloured orange bark underneath. Indeed the peeling bark is somewhat reminiscent of a bad case of sunburn where the skin gradually peels off through the summer.
But also, towards the end of summer, Angophora costata produces bold displays of big, white fluffy flowers which are absolutely dripping with nectar, attracting nectar-feeding birds. The gnarly habit of the trunk also lends itself to producing hollows, in which the various parrot species can nest.
So it’s a great ornamental tree and it’s interesting to see that it’s also commonly planted around Melbourne, although when it’s grown in more favourable conditions, it tends to grow with a much straighter trunk and does not develop the gnarly habit that you see consistently in the Sydney sandstone country. However, it’s still a beautiful tree without that gnarled habit, as you have the bark, the flowers in summer and its ability to attract a great suite of birds.
The genus Angophora is closely related to the eucalypts and, in fact, a group of eucalypts, the bloodwoods, have been split off and put in another genus called Corymbia because they are actually more closely related to Angophora than Eucalyptus. So it made sense to have three different genera – Eucalyptus, Corymbia and Angophora. Corymbia and Angophora share the way their flower heads are held right on the ends of the branches making the most spectacular display. Perhaps the best known Corymbia is the red-flowering gum, Corymbia ficifolia from Western Australia, with its vivid displays of scarlet flowers held at the ends of the branches.
So Angophora costata is worth considering but, if you have a smaller garden, have a look at its close relative the dwarf apple gum, Angophora hispida, as it grows to only several metres and is often more like a shrub than a tree. It also has spectacular clusters of white flowers on the ends of the branches, and rusty hairs on the flowers and new growth. So between Angophora costata and Angophora hispida, there’s one for many Australian gardens.