Gum Tree Eucalyptus mannifera

The trunk on a Brittle Gum runs through a full colour cycle every year. Fresh bark comes out white to pale grey with a powdery bloom you can rub off with a thumb, ages through cream to pink and red brown over summer, then sheds in ribbons and starts again. Above it sits an open crown of narrow blue green leaves and small white flowers, casting light rather than dense shade, so grass keeps growing underneath. It is grown as a trunk feature on large gardens, parks and rural entries.

Tableland gravel, and a tree that drops branches

This is a tableland tree from the Canberra region and the nearby ranges, so hard frost, long dry spells and shallow, poor, gravelly soil are all within its range once established. It performs through the ACT, the Southern and Central Tablelands, central Victoria and cooler inland districts, and it will manage in drier coastal gardens with good drainage. Full sun brings out the bark colour. Avoid winter wet ground and avoid siting it in a lawn that gets constant summer irrigation, which produces soft growth and dulls the trunk.

Take the common name seriously, because it is the failure mode. The wood snaps at the branch union rather than bending, and this tree sheds branches through its whole life rather than only in old age, on a still afternoon as readily as in a blow. That matters more than it sounds, because a brittle gum is not an enormous tree and people site it close in on exactly that basis, over a carport, beside a play area, above a parked car. Pruning does not solve it either. Reducing the crown triggers a crop of fast, weakly attached regrowth that fails more readily than the wood you took off. Distance is the only real answer, so give it open ground where a falling branch lands on grass and then leave the tree alone.

Brittle Gum beside inland scribbly gum

It sits close to inland scribbly gum, another smooth barked tableland species from much the same country. The difference is what the bark does. Scribbly gum carries the wandering moth larvae trails that give it its name and holds a paler, quieter trunk, while Brittle Gum works through white, pink and red brown over the season. For a much smaller tree with a white trunk on a suburban block, Wallangarra white gum is the safer choice. Plant Brittle Gum where you have paddock scale room and want the trunk lit at night. There is a safety difference too. Scribbly gum sheds bark and small branches, but Brittle Gum earned its name from genuinely weak wood, so it needs more clearance from anything you value. More advanced stock in mature trees.

Structure while the wood is still soft

Get the structure right early, because pruning options narrow as the wood hardens. In the first few years, select a single leader, shorten competing stems while they are finger thick, and remove narrow forks with included bark, since those are where limbs later fail. Work in late winter. On established trees, restrict pruning to deadwood and to branches over targets, and have anything large done properly rather than topping it. Feeding is barely required. Two early applications of a native blend, mulch to the dripline, and no lawn fertiliser over the root zone, since turf feeds carry the phosphorus this tree does not want.

Choosing a size

This plant is available in 7 sizes, from 140mm up to 200L, priced from $16.95 to $1209.00 per plant. The size shown is the pot the plant arrives in, which is the rootball, not the height of the plant. The smaller pots hold younger plants that cost less each and establish quickly, which suits hedges, screens and mass planting where the plant count adds up. The larger sizes carry several more years of growth on the farm and give height and presence straight away, which is what you want for a single feature position or a screen that cannot wait. Not sure which to choose? Read our guide to Australian native trees for shade.