Gunnera is known as giant rhubarb, because it really does look like a colossal, prehistoric version of our more familiar culinary rhubarb. This Chilean giant is definitely not edible, but it is a spectacular plant with the epic, architectural foliage making a real impact in big gardens with ponds. The clumps of prickly leaves and stalks make a very large plant that is a stunning feature if you have the space. There are, however, smaller varieties of gunnera which will suit other garden situations.
Take a look at our handy gunnera Grow Guide, below.
Where to plant gunnera
Grow Gunnera in moist, humus-rich soil in a sheltered spot in full sun to partial shade. It needs lots of space and looks best grown as a specimen plant in a bog garden, or at the edge of a pond or stream.
Planting gunnera
Buy a small plant and dig a generous hole, adding in some well-rotted compost. Leave plenty of space around the plant for your gunnera to grow into.
Propagating gunnera
Gunneras can be grown from seed, saved from the flower spike. Alternatively, you can take basal cuttings in spring from new growth.
Gunnera: problem solving
Gunneras are generally pest and disease free.
Care
Gunneras are herbaceous perennials so the spectacular foliage will die back at the end of the summer. In autumn, use the dead leaves to fold over the crown of the plant to protect the fat new buds within from frost damage.
Gunnera varieties to try
- Gunnera manicata – the best known of these giant foliage plants, is a rhizomatous, clump forming perennial. The Royal Horticultural Society has given it the prestigious Award of Garden Merit
- Gunnera tinctoria – has more rounded, deeply lobed leaves than Gunnera manicata, and shorter leaf stalks. The flowering spike is shorter and its individual spikes smaller and less open. Gunnera tinctoria is considered an invasive plant in parts of the British Isles
- Gunnera magellanica – a dwarf, spreading variety with leaves that look like miniature versions of the giant varieties. It makes excellent ground cover in damp, boggy soil and is hardy to -10°C
- Gunnera perpensa – a South African variety, known as River Pumpkin, that is also hardy in the UK. This is also smaller than its South American relatives, growing to around 60cm. The leaves have a light mottled pattern and a green flower spike appears in late summer
