Giant Rhubarb is One of the Most Enormous and Spectacular, Architectural, Herbaceous Plants on Earth. Thought to be around 150 Million Years Old and First introduced into Europe in the 1860′s it is often called Dinosaur Food or Giant Rhubarb due to its Gigantic, Deeply Lobed, Deep Green Leaves, which Grow up to 6' Feet Across. This is the Granddaddy of Big-Leaved Perennials.
No other Plant can so Thoroughly Alter the Scale of a Garden while Calling such Attention to Itself. The Architectural Leaves Grow up to 6 feet across. They are Rounded and Deeply Toothed and Sit atop Prickly Stalks that extend to 10 Feet Tall and Form Giant Clumps. Gunnera manicata Produces Large, Bottle-Brush Spikes of Tiny Reddish-Green Flowers in the Spring. It looks Particularly at Home at the Water's Edge and Thrives in its Boggy Soil.
Gunneras Need a Lot of Space because it is Difficult to Restrict their Size. They Look Best Standing as Specimen Plants in a Damp Bog Garden, or beside a Large Pond where the Reflections Reveal the Undersides of the Leaves. The Stalks hold Tiny Red-Brown Flowers on Erect Panicles up to 3' Feet in Height, Followed by Small Red Berry-Like Fruits. The seed size is Incredibly Small One of the Most Gigantic Plants in the World, the Seeds are as Small as a Poppy Seed.
The Fat Growth Buds Clustered in the Crown are Prone to Frost Damage, so Pile the Dead Leaves and Stems into a Mound over the Plants in Autumn for Winter Protection. Gunnera manicata is Easy to Grow. Good Soil with Steady Moisture, by a Pond or Stream Perhaps, and a Great Deal of Space is All you Need to Enjoy this Magnificent Prehistoric Plant but can be Planted anywhere in your yard as long as you keep the soil wet and do not let it dry. Gunneras can be grown in Zones 6 - 9b as long as adequate protection is provided in the fall before winter sets in. The most ideal zones would be 9-11.