Gunnera manicata or Giant Rhubarb is a hardy plant that will have one hell of an impact on your garden, provided your garden is big enough… because it can be as high as 3 m with a spread of 4 m.
Although originally from Brazil, it is capable of resisting temperatures of -20 °C with protection.
It prefers to be planted at the edge of a water feature or a very moist soil but in the winter, it prefers dry soil.
Contrary to what its name giant rhubarb suggests, the plant is not related to rhubarb and is not edible.
Gunnera manicata is perennial and has a running rhizome.
The leaves, borne on a stalk of 1.5-2 m long, are enormous: up to 3 m in diameter under good conditions. The leaves are lobed and toothed. The underside of the leaves and the stalks are covered with thorns.
The hermaphroditic flowers are small, green and worn on a long spike (80-120 cm). It blooms in spring but the flowers grow and mature slowly until the fall.
The fruits are round, red-green and 1 to 3 mm long.
Dinosaur Food, Giant Gunnera, Giant Rhubarb
Gunnera: in honour of the Norwegian botanist Johan Ernst Gunner
Manicata: from the Latin manica (handle)
Andes in Brazil and Colombia
USDA zone 6-8, -10 °C. With winter protection: -20 °C.
Fertile and wet at all times, preferably at the edge of a water feature
Sun to partial shade
The soil needs to be wet at all times
Give fertilizer weekly during the growing season
Protect the base of the plant in autumn to increase frost resistance
Seed (not recommended: seeds lose their viability very quickly), suckers, division of the rhizome
- sow in spring in a light substrate
- maintain the substrate moist at all times
- 25 tot 27 °C
- do not expose to direct sunlight while germinating
- germination: 1-2 months