Description

General aspect and origins - Gunnera manicata syn. Gunnera brasiliensis is also known as giant rhubarb. It is a perennial herbaceous plant which is native to the mountains of Brasil and Colombia.
Leaves - This plant has huge decidious leaves, that can be up to 8 ft (2,40 m) wide in its native area. Leaf stems are thorny, and can be up to 4 or 5 ft. (Up to 1,50 m)
Flowers - Gunnera manicata has tiny green-red flowers, which are grouped in erected inflorescences. These inflorescences bear both male and female flowers.
Fruits - This plant bear tiny red-green fruits, which are about .1 in (2.5 mm) long.

Culture

Giant gunneras are huge ornamental plants that need a lot of space, which are fitted for big gardens with damps areas or ponds. The leaves usually die back in winter, but the plant itself with survive lower temperatures, down to about 14°F (-10°C) and even lower with some protection. This plant can thus be grown in USDA zones 8a and warmer, and could be tried in sheltered places in zones 7.
Soil - These plants thrive in damp bog conditions, in a moist and fertile soil.

Propagation

The giant rhubarb can be propagated by offshoot division or by seeds. It is best to use fresh seeds for good results.