Gunnera tinctoria, known as giant rhubarb or Chilean rhubarb, is a flowering plant species native to southern Chile and neighbouring zones in Argentina.
That said, rhubarb is a heavy feeder, so apply compost annually or an all-purpose fertilizer according to the manufacturer's instructions early in the spring. If you live in a warmer region, mulching around the base of the plant will help keep the soil cool and moist. Keep the soil moist but not sodden.
When planting Riverside Giant rhubarb crowns, choose an area of full sun to partial shade with deep, rich, and moist but well-draining soil in the spring. Dig a hole that is wider than the crown and deep enough to that the eyes are 2-4 inches (5-10 cm.)
We recommend cutting the flower spikes close to their base, with a gardening knife or pruning saw, in July or August.”
Rhubarb is a perennial that loses its leaves in the fall and then requires a winter chilling period to produce in the spring. Rhubarb can be grown in USDA zones 3-7 and tolerates temps as low as -40 F. (-40 C.).
Although Giant rhubarb is not poisonous to humans, the leaf blade and stem bear stiff bristles which can scratch skin. Brazilian giant-rhubarb is very similar to giant-rhubarb with leaves reaching over 2 m across, leaf stalks with reddish bristles and spines and the inflorescence up to 1.2 m tall. Giant-rhubarb is spread throughout lowland areas especially in south-west England.
