Cadaghi tree

How to identify a cadaghi

Cadaghi is a tall gum whose trunk has a stocking of rough, scaly, grey-brown bark on the lower few metres and smooth, pale greenish-grey bark above, which turns grey with age. Unlike most gums, its leaves are broad, pale green and rough to the touch from short stiff hairs, and they are often blackened by sooty mould. Masses of small white to cream flowers form clusters at the branch tips, followed by small round or urn-shaped capsules. Big limbs spread out almost at right angles to the trunk, and seedlings have reddish, hairy stems.

Growing a cadaghi in Brisbane

Cadaghi is not native to South East Queensland. It comes from the coastal ranges of north Queensland, and around Brisbane it has spread from gardens and streets into bushland, creek lines and roadsides. Native bees gather the sticky, resin-coated seeds and carry them into eucalypt forest, where the dense crown shades out the plants underneath. It has also been recorded crossing with spotted gums in northern New South Wales. Because it is a recognised weed here, it is not a tree to plant in Brisbane.

What to watch out for

Brisbane City Council lists cadaghi as pest vegetation, and it is regarded as an environmental weed in South East Queensland. Its large horizontal limbs are prone to snapping and can damage property, so trees near houses, cars and play areas need checking. The leaves often carry sooty mould that drops grime on cars, paving and outdoor furniture. Stingless bees collect the sticky resin from its fruit, and it can clog their hives and even seal the entrance, killing the colony. Like other large gums, keep it away from pipes.

• Seedlings. Native bees carry its resin-coated seeds into bushland, and wind, water and dumped garden waste spread it too.
• Dropping limbs. Its large horizontal limbs are prone to snapping off and can damage property.
• Mess. Sooty mould on the leaves can drop grime onto cars, paving and outdoor furniture.
• Size. It can grow to 30 metres with a dense, heavy crown.

Pruning and care

With a cadaghi, care mostly means management. Pull out seedlings while they are small, and don't dump prunings or seed capsules in bushland. Have large horizontal limbs checked, especially over roofs, driveways and play areas, because they are prone to snapping. Brisbane City Council's weed guide lists the cut stump method, basal bark treatment, stem injection and foliar spray as control options. A mature tree is a job for a professional, who can take it down in sections and grind the stump.

• Tree removal
• Stump grinding
• Tree pruning
• Storm damage cleanup