How to Care for Gunnera
Plant gunnera in shade and moist, fertile soil. It will tolerate part sun well as long as the soil is never allowed to dry out. Gunnera is intolerant of hot or dry climates and also balks at cold temperatures. In Zone 7, plant gunnera in a site that is protected from cold, drying winter winds. When preferences for moist, humus-rich soil and shade are met, it is easy to grow and spreads to form a lush clump. Plant gunnera in early spring and water it well after planting. Continue to water plants regularly, especially if the soil is not naturally wet, to encourage a strong root system. Cover the soil with a 2-inch-thick layer of mulch to prevent soil-moisture loss. Tiny red-green flowers rise from the center of the plant on thick spikes in early summer. The flower spikes form berrylike fruit. Gunnera is rarely troubled by insects or diseases. Remove the occasional damaged or dead leaves as soon as they appear. In Zones 6 and below, gunnera can be grown in the garden, then dug up and stored inside during winter. Dig and lift the roots in fall before the first frost. Store them in a dry medium, such as peat or vermiculite, in a cool area where the temperature remains at about 40°F. Plant the bare roots outside as soon as the danger of frost has passed. When grown in a container, this plant can be moved inside to a frost-free location, such as an unheated garage or basement, where it will go dormant while waiting out the winter. Water it minimally every 10 days or so until it’s time to be replanted outside.
