How to Grow Gunnera

Gunnera are evergreen or herbaceous perennial plants, some varieties forming a creeping habit and others a large and vigorous habit with enormous leaves. Flowers are small and form in clusters or spikes. Some varieties can produce small berries. Gunnera are best suited to an architectural or informal city garden. You should expect to see your plant grow to an approximate height of 2.5 metres (8’) and a spread of 4 metres (13’).

Gunnera are best planted in moist, poorly-drained soil of clay or loam within an acidic, alkaline or neutral PH balance. Choose a site that receives part shade and where the soil will stay cool and moist. Amend the planting area by loosening the soil and mixing a generous amount of compost. Dig a hole that is twice the diameter of the root ball so that it is level with the soil surface. Once settled in place, firm the soil and water thoroughly.

Gunnera are easy to care for once established. However, ensure they are protected during periods of cold weather and frost as they do suffer is temperatures drop below 14°F (-10°C). During autumn you may wish to remove all the leaves to retain a neat and tidy appearance during the winter. Cover the stump with the leaves to protect it against frost and cold winter air.

It is possible to propagate Gunnera by division during the spring.