Credit: David Foley
Melianthus major
Background and story
The Honey Bush (Melianthus major) is a bold, evergreen subshrub native to the Cape region of South Africa, long admired for its dramatic foliage.
It has been grown in Ireland and Britain since at least the 17th century, and was a notable feature of earlier ornamental gardens.
Its most striking characteristic is its large, blue-grey, pinnate leaves, often up to 45 cm long, with deeply serrated edges that give a strong architectural effect.
In warm seasons, it produces tall spikes of tubular maroon flowers, rich in nectar and adding an unusual vertical accent, though it is primarily grown for foliage rather than bloom.
Did you know?
When brushed against or crushed, the foliage releases a strong, unusual scent often compared to peanut butter or salty nuts, likely acting as a deterrent to grazing animals.
Hardiness and conservation
The recorded RHS hardiness rating is H3, which means this plant is generally hardy in coastal and relatively mild districts, especially where drainage and shelter are good. The recorded USDA/PFAF hardiness value is 7-10, 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 Not Assessed (NA).
Additional notes for Ireland and Britain
In Ireland and Britain, Melianthus major is borderline hardy but widely grown, particularly in mild, sheltered gardens. It thrives in full sun and moderately fertile, moist but well-drained soil, and typically reaches 1.5–2.5 metres in height and spread over time. In colder conditions, the top growth may be cut back by frost, but the plant often reshoots vigorously from the base, meaning it is frequently treated more as a herbaceous perennial than a true shrub. It performs especially well in coastal or urban microclimates, and is often used in exotic-style planting for its bold texture. Protection from cold, drying winds and a dry winter mulch can significantly improve performance.
From a conservation and hardiness perspective, Melianthus major is not considered threatened, with stable populations in its native South African range and widespread cultivation. It holds the RHS Award of Garden Merit, reflecting its reliability under suitable conditions. In terms of hardiness, it is classified as RHS H3, meaning it tolerates temperatures down to around −5°C in sheltered locations, but is vulnerable to prolonged frost and winter wet. Its main limitation in Irish gardens is therefore exposure and severe cold, rather than rainfall alone. In an Irish context, it is a high-impact but slightly tender plant, capable of strong performance where microclimate is favourable.
Notable features
- It produces black (or very dark) nectar. One of the most unusual features is its copious, dark nectar, held in cup‑like structures within the flowers. This nectar attracts birds such as sunbirds in its native habitat.
- It is highly toxic despite its lush appearance. All parts of the plant contain powerful cardiac glycosides (bufadienolides), making it dangerous to humans and animals if ingested.
- The flowers twist upside down after opening. The blooms undergo a process called resupination, twisting through 180° after opening so that they hang downward, positioning the nectar for visiting birds and pollinators.
- It spreads by suckers to form large colonies. Rather than staying as a single plant, it sends up new shoots from the base, allowing it to expand into wide, interlinked clumps over time.
Earlscliffe notes
We first planted it on a bank beside a newly built house, simply to see if it might provide quick ground cover. It certainly did — in fact, it proved so vigorous that we had to cut it back regularly to keep it in check.
We also noticed that the distinctive “peanut butter” scent is remarkably strong, although opinions vary and not everyone finds it pleasant.
We now grow it in a more exposed, south-facing position where it takes a fair amount of wind; in this spot it behaves rather differently, less rampant but still healthy, and arguably better balanced for it.