Credit: David Foley
Eucalyptus leucoxylon
Background and story
The Large‑fruited Yellow Gum (Eucalyptus leucoxylon subsp. megalocarpa, often known in horticulture as var. macrocarpa) is a distinctive form of the widespread Eucalyptus leucoxylon, native to southeastern Australia, particularly South Australia and Victoria.
Within this variable species, it is recognised for its larger fruits and often larger, more showy flowers, which can range from white to pink or red, sometimes in particularly vivid shades that have made it popular in ornamental planting.
It typically forms a small to medium-sized tree, usually up to about 10 metres, though sometimes smaller, and has smooth bark that sheds to reveal pale grey, cream or bluish tones.
Like many eucalypts, it also carries aromatic foliage and belongs to a complex group where subspecies distinctions reflect regional variation as much as clear structural differences.
Did you know?
The name macrocarpa means “large-fruited”, which suits this subspecies because its woody seed capsules are noticeably larger than those of many other forms of Eucalyptus leucoxylon.
Hardiness and conservation
The recorded RHS hardiness rating is H4, which means this plant is usually hardy through most typical UK and Irish winter conditions, although exposed or wet sites can still cause losses. The recorded USDA/PFAF hardiness value is 10-11, which is useful as a broad winter-temperature guide, but it should not be read as a direct substitute for the RHS rating. Local hardiness always depends on local shelter, drainage, winter wet, salt-laden wind and the plant’s age and establishment.
The IUCN Red List status recorded here is Vulnerable (VU). This places it in a threatened category, with a high risk of extinction in the wild. The assessment year recorded in the plant data is 2019.
Additional notes for Ireland and Britain
In Ireland and Britain, Eucalyptus leucoxylon subsp. megalocarpa is one of the more promising flowering eucalypts, but still somewhat site-dependent, performing best in sheltered, sunny locations with free-draining soil. It can develop into a small, rounded tree (roughly 6–10 metres) with a relatively compact canopy compared to larger eucalypts, and is valued for its potential to flower more reliably in cooler climates than some red-flowering species. It prefers warmth and good light, and benefits from shelter from cold winds when young. As with most eucalypts, it dislikes waterlogging and shade, and while growth can be reasonably fast once established, flowering may still depend on favourable conditions.
From a conservation and hardiness perspective, the broader species Eucalyptus leucoxylon is not considered threatened overall, though some natural populations in Australia are affected by land-use change and habitat loss. In terms of hardiness, this subspecies is generally moderately hardy rather than fully robust, roughly comparable to RHS H3–H4, tolerating light to moderate frost (about −5°C to −10°C when well established), though younger plants are more vulnerable. Its main limitation in Irish conditions is exposure and winter wet rather than cold alone, and success depends heavily on microclimate, particularly in coastal or urban settings. In an Irish context, it is a useful but slightly adventurous flowering tree, offering colour and structure for those prepared to provide the right conditions.
Notable features
- This subspecies is known for producing larger flowers and fruits than typical Eucalyptus leucoxylon, often with showy colours ranging from cream to deep pink or red, making it one of the more ornamental gums
- It belongs to a highly variable species complex, meaning different populations can look quite different, which is why it has been classified as a subspecies rather than a separate species
- The flowers are rich in nectar and are especially attractive to birds and pollinators in their native habitat, contributing to local ecosystems.
- Unlike many large Australian eucalypts, it typically forms a smaller, more compact tree, making it more manageable in cultivated landscapes
- The smooth bark sheds in patches to reveal pale underlying tones, a characteristic feature of many gums, giving the tree year-round visual interest beyond its flowers
Earlscliffe notes
The Red Flowered Yellow Gum (Eucalyptus leucoxylon subsp. macrocarpa) flowered for the first time at Earlscliffe in August, 2002. This plant was raised from seed sown in 1996 and has proved to be much hardier than the Red Flowering Gum Eucalyptus ficifolia, large numbers of which, sown at the same time as E. leucoxylon, perished in the cold 2000/01 winter. We thought that this tree died in the winter of 2009/10. However, it started to grow again at the base of the tree and now often flowers in late autumn.