The gunnera plant (Gunnera manicata), also known as giant rhubarb and dinosaur food, is native to bogs and high-elevation forests in South America. This giant plant grows from a tuber to eventually reach over more than 6 feet tall, with a 10-foot spread. Gunnera leaves can reach 8 feet in diameter, have a sandpaper-like surface and are shaped to funnel water the plant's roots. Wear gloves when handling the plant to avoid punctures from the thorny stems. Other than a high moisture requirement and some humidity, gunnera is an easy plant to grow.
Grow the gunnera plant in dappled shade, if possible. In nature, gunnera grows in the forest understory, so mimicking the conditions will help the plant thrive.
Water the gunnera plant to keep the soil wet at all times. If you are growing it in a container, place the container in a tray of water, or in a fountain or other water feature. Never let the soil dry out.
Feed the gunnera plant, in early spring and in midsummer, by adding 2 inches of compost or well-rotted manure to the soil and mixing it in to the top 4 inches of soil. Water well after adding the amendments.
Protect the gunnera from winter temperatures that dip below 20 degrees F. After the first frost, cut off all foliage, to the base of the plant, and lay the leaves, inverted, over the plant's crown. For extra protection, pile 10 to 20 inches of straw on top of the leaves.