Flooded gum

How to identify a flooded gum

A very tall, straight-trunked gum with smooth, powdery bark in white or pale grey above a short skirt of rough, flaky grey bark on the lowest 1 to 4 metres. Thin ribbons of shed bark often hang in the upper branches. Adult leaves are glossy and lance-shaped, 10 to 18 cm long, dark green on top and clearly paler beneath. Small white flowers come in groups of 7 to 11 and are followed by cone-shaped gumnuts 4 to 10 mm long, often with a bluish bloom and four or five valves that curve inward. Sydney blue gum looks similar but has a lignotuber, buds without the bloom and gumnuts with four upright valves.

Growing a flooded gum in Brisbane

Flooded gum is a local. The species was first described from a tree near Brisbane, and it grows naturally from near Newcastle to Bundaberg, with smaller stands further north. It favours deep, moist, well-drained loams on creek flats and in gullies, and the City of Moreton Bay lists it as a koala habitat tree. It suits acreage, farms and large parks with room for a 50 metre tree, and can form a tall windbreak on big blocks. On a suburban lot it will outgrow its space and end up over houses, sheds or power lines.

What to watch out for

This is a forest giant. Business Queensland gives a height of 45 to 55 metres and a trunk 1 to 2 metres across, and EUCLID notes its size limits its use in gardens. The Australian National Botanic Gardens points out that all eucalypts shed limbs, so large species shouldn't be planted where they will overhang homes. Unitywater lists large gum trees among the plants not to put near water and sewer pipes, and Hunter Water rates large gums as a very high risk to sewers.

• Size. It commonly grows 45 to 55 metres tall with a trunk 1 to 2 metres across, and EUCLID notes that its size limits its use as an ornamental.
• Dropping limbs. All eucalypts shed limbs, and the Australian National Botanic Gardens advises against planting large gums where they will overhang houses.

Pruning and care

Plant it only where it has room to reach full size. Young trees grow quickly and appreciate a deep watering through long dry spells while they establish. Gums are best left to form their natural shape: prune only to remove dead, damaged or hazardous branches, cut just outside the branch collar, and never top the tree. Because eucalypts shed limbs, have an arborist inspect large trees near homes, driveways or play areas. Work high in a tree this size is strictly a job for a qualified arborist.

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