- Mature height
- 10m to 30m (approx.)
- Mature width
- 7m to 15m
Eucalyptus ovata, the Swamp Gum or Black Gum, is a medium native tree with a rounded, upright crown. Juvenile leaves are broadly oval, which gives the species its name, and adult leaves are glossy dark green. Rough grey bark holds on the lower trunk, with smooth bark shedding in ribbons above.
It grows on ground other eucalypts refuse: heavy clay, seasonally flooded flats and poorly drained corners. Full sun to part shade suits it. It is frost hardy through heavy and frequent frost, with moderate drought tolerance. Growth is 1 to 1.5 metres a year. Best in Tasmania, Victoria, southern New South Wales and South Australia.
It is used for revegetating wet flats and creek margins, for farm shelterbelts, and in civic parkland and avenue planting where the ground stays damp. The winter and spring flowers matter for wildlife in the cold months. At 12 to 20 metres with a canopy to 15 metres, it is a shade tree for open ground.
Frequently Asked Questions
About Swamp Gum
What is Eucalyptus ovata?
Eucalyptus ovata, called Swamp Gum or Black Gum, is an evergreen native of Tasmania, Victoria, southern New South Wales and South Australia. It grows naturally on poorly drained flats and creek margins. The name comes from the broadly oval juvenile leaves. Adult foliage is glossy dark green and the lower trunk carries rough grey bark.
How big does Swamp Gum grow?
It reaches 12 to 20 metres tall with a broad canopy of 7 to 15 metres. Trees on damp, fertile flats reach the upper end of that range, while those on drier ground stay smaller. It is a full-sized shade tree, so plan around the wider canopy figure rather than the height when choosing a position.
Will it grow in wet or boggy soil?
Yes, and that is what sets it apart. It grows naturally on swampy flats and tolerates soil that is waterlogged for weeks at a time as well as periodic flooding, which is why it is used for revegetating wet gullies, dam surrounds and drainage lines. It also copes with heavy clay that stays cold and wet through winter.
Does it need sun or shade?
Full sun gives the best form, but it is more shade tolerant than most eucalypts and will grow acceptably in part shade, including under the edge of an existing canopy. In heavy shade the crown thins and the trunk stretches. For a shade tree or shelterbelt, open the position up and give it full light.
When does Swamp Gum flower?
Flowering runs through winter and into spring, and can begin in late autumn in warmer districts. The flowers are small, white to cream and held in clusters of seven. Because they open in the cold months, they are an important nectar source for honeyeaters, swift parrots in Tasmania and native bees when little else flowers.
Is Swamp Gum frost tolerant?
Yes. It is frost hardy and survives heavy and frequent frost without damage. It occurs naturally in cold, frost-prone hollows in Tasmania and the Victorian highlands where cold air pools, so it handles the sites that damage less hardy trees. No protection is needed beyond ordinary care in the first year.
How do I care for Swamp Gum?
Water through the first two summers, though on naturally damp ground it will need less. Mulch the root zone and keep the mulch off the trunk. Skip phosphorus-rich fertiliser. Prune in the first few years for a single leader and clear trunk, then only to remove deadwood or limbs over paths and fences.