Gum Tree Eucalyptus tricarpa

The name tricarpa points to the buds and gumnuts, which hang in threes on a stout stalk. The bark is the real signature, though: deeply furrowed, almost black, hard and held right out along the branches, with narrow grey green leaves above it. Flowering runs through the cooler months when little else is out, and the colour varies from tree to tree, cream through to strong pink. Dark trunk, winter nectar and an upright forest habit put it into habitat plantings and large rural gardens.

Gravel country, and a flower colour you cannot choose

It comes from the box ironbark country of central Victoria and southern New South Wales, so gravelly soil, drought and full exposure are its normal conditions, and it takes frost without trouble. It suits inland Victoria, the slopes and tablelands of New South Wales, the ACT and drier parts of South Australia. Full sun, and no soil improvement. Growth is fast in open ground once the roots are established, and water demand drops right away after the first couple of summers. It will not take heavy clay that holds water through winter, where the roots rot and the crown thins from the top, so mound the bed if drainage is doubtful and do not irrigate it once established. Flowering through the cold months makes it valuable to beekeepers and to honeyeaters, and older trees carry the hollows that parrots use.

The honest weakness of Red Ironbark is the flower. Colour runs from cream through to strong pink, and it is set by the individual tree rather than by the season, the soil or anything you do, so a seedling raised plant is a lottery and no amount of feeding, pruning or patience will turn a cream tree pink. A catalogue photograph is not a promise on this species. If the pink is the reason you are buying, buy a plant already in flower, or plant several and accept that you are playing the odds. If the winter nectar and the black trunk are the reason, colour does not matter and any tree in the batch does the job just as well.

Red Ironbark with yellow box and grey box

Its natural partner in a planting is yellow box, which flowers in the warm months and carries rough box bark low with smooth limbs above, where this one is dark and furrowed to the branch tips and flowers in the cold. Between the two you cover most of the nectar year. Grey box is the denser, more shade giving option on heavier ground. Choose Red Ironbark for dry gravel, winter flowering and a trunk that reads almost black in the landscape. Bark is also the fastest way to tell them apart at any distance, since both boxes shed to smooth pale limbs above the trunk while the ironbark stays dark and deeply furrowed to the ends of the branches. See more in advanced trees.

Sparing cuts on ironbark wood

Prune sparingly. Ironbarks build sound structure on their own if you select a leader early and shorten competing stems in the first few years, and they respond poorly to large cuts later, so get it right while the wood is small. Late winter, after flowering has finished, is the window. Feeding is close to unnecessary and can do harm, since this is a species from low fertility gravel. Use a low phosphorus native fertiliser once in spring for the first two seasons if the tree is in made ground, then rely on coarse mulch and grass control around the base.

Choosing a size

This plant is available in 3 sizes, from 300mm up to 45L, priced from $88.95 to $259.00 per plant. The size shown is the pot the plant arrives in, which is the rootball, not the height of the plant. Every size here is established stock rather than a starter plant, so this line is intended for immediate effect rather than for growing on. Not sure which to choose? Read our guide to Australian native trees for shade.