Credit: David Foley
Aeonium arboreum 'Atropurpureum'
Background and story
A cultivar of the Canary Island species Aeonium arboreum, ‘Atropurpureum’ is valued for its dramatic foliage and architectural habit. The rosettes sit at the tips of woody stems, forming a small, open shrub that contrasts strongly with brighter greens and silvers in planting schemes.
The parent species has been known here since at least the 17th century, appearing in early cultivated collections such as the Badminton Florilegium, but it was during the 19th‑century period of botanical exploration that Aeonium arboreum became widely established in European horticulture.
Collected and described from the Canary Islands by botanists working with Kew, including Joseph Dalton Hooker, it quickly became a conservatory favourite and later a garden plant in milder coastal climates.
The dark-leaved form ‘Atropurpureum’ is a cultivated selection rather than a wild plant. Although purple forms were long present in gardens, the cultivar itself was formally described in 1959 by Dr B. K. Boom.
Did you know?
It earned the nickname “Irish rose” despite not being Irish. The name comes from its rosette shape resembling a rose, combined with its long presence in cultivation in Ireland and Britain, particularly in mild coastal gardens.
Hardiness and conservation
The recorded RHS hardiness rating is H1C, which means this plant may be grown outside in summer, but still needs frost-free winter protection. 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 Irish and British conditions, Aeonium arboreum ‘Atropurpureum’ is best understood as a marginally hardy, climate‑dependent plant. It tolerates drought, wind and poor soils, but is sensitive to frost, generally surviving only light freezes if kept dry. In warm, sheltered gardens it can develop into a small, woody shrub up to 1–2 metres tall, with a distinctly Mediterranean character.
The cultivar ‘Atropurpureum’ has no formal conservation status, as it is a horticultural selection. The species Aeonium arboreum itself is not considered threatened, being widespread in its native Canary Islands and widely naturalised and cultivated elsewhere. However, many aeoniums are island endemics, and while this species is secure, the genus as a whole includes rarer taxa of conservation interest.
Notable features
- It’s effectively a colour-shifting plant. The deep purple colour isn’t fixed. In lower light it reverts toward green, while strong sun drives it towards near-black through increased anthocyanin pigments.
- It follows a Mediterranean growth rhythm, not a succulent one. Unlike agaves or aloes, it grows mainly in cool, damp seasons (autumn to spring) and partially shuts down in summer, often visibly tightening or “closing” its rosettes.
- Each rosette has a built-in end point. Like most aeoniums, each rosette flowers once and dies, but the plant avoids disappearing by branching, so the overall shrub can persist for many years.
- It was once mistaken for a completely different genus. Early botanists classed it as a tree-form Sempervivum before the genus Aeonium was formally separated in the 19th century.
Earlscliffe notes
At Earlscliffe, they have been successfully growing outdoors all year round. They are checked by a little frost and prefer south-facing sunny slopes. We are not exactly sure which specific variety we have, however, it is most likely Aeonium arboreum 'Atropurpureum' .