Common name: Brazilian giant rhubarb, giant rhubarb, devil's strawberry
With the largest leaves of any hardy perennial and the appearance of a giant rhubarb, Gunnera manicata makes an impressive statement in a garden large enough to accommodate their huge size. However, there is a small one called Gunnera megellanica to seek out. They are great plants for wet soil on the margins of a large natural pond in gardens, but make sure they don't escape as the larger ones are invasive in the wild (see Good to Know below).
Huge, deeply veined, jagged-edged leaves are held horizontally on robust, upright, prickly stems. Large, conical spikes of reddish-green flowers emerge around the base of the plant in late spring. Protect plants from freezing weather in winter by folding the decaying leaves over the crown in late autumn.
Gunnera revel in permanently damp soil. They need shelter from strong winds and protection from extended freezing conditions. Gunnera prefer to grow in sun or light shade.
Growth will be poor on dry soils or in deep shade. Frost can damage the crown of the plant if unproteced over winter.
Did you know?
Gunnera manicata can be invasive, particularly when planted along a water course. As a result it is listed on Schedule 3 of the EU (Birds and Natural Habitats) Regulations 2011 in the Republic of Ireland as an invasive non-native species. While this does not prevent it from being sold or from being grown in gardens in the Republic of Ireland, the RHS encourages those that do grow it to take great care with managing it and with disposing of unwanted material. Stricter rules apply in the whole of Europe and UK for Gunnera tinctoria - it is an offence to plant or cause these to grow in the wild. It is banned from sale and gardeners growing this plant should undertake measures to control its spread beyond their garden.
The Royal Horticultural Society is the UK’s leading gardening charity. We aim to enrich everyone’s life through plants, and make the UK a greener and more beautiful place.