Gunnera (also known as Chilean rhubarb) is known in other regions in New Zealand to shade out other plants, form thick stands/clumps and to spread to bluffs, wet cliffs and near waterways.

Gunnera is a large, clump-forming, summer-green herb, up to 2m tall with large sized leaves on sturdy stalks. Both leaves and leaf stalks are covered in rubbery red prickles. Gunnera dies down over winter in cold climates and grows new leaves in spring from large, lobed, scaly buds that are pinkish-green when fresh and dry to brown. It produces small densely packed green flowers in summer on long, stiff, pointed spikes that develop into reddish, oblong fruit, each containing a single seed.

There are no rules for landowners in Otago regarding gunnera. Under Otago’s pest plan, gunnera is only classified as a pest in the site-led areas; Otago Peninsula, West Harbour/Mt Cargill, Quarantine Island and Goat Island.

The goal is to progressively contain gunnera in these areas to prevent or improve on damage to the indigenous ecosystem values at these sites.

ORC will take a lead role in supporting the goals of community groups and agencies in site-led areas in relation to gunnera. This may be through advice, education, funding, service delivery or requiring landowners to undertake control when needed.

• Remove flower spikes and dispose at landfill
• Pull out individual plants and seedlings. Ensure removal of all rhizome (an underground fleshy stem) fragments and seed/flower heads and dispose at landfill
• Cut and paste the stump near the ground using a suitable herbicide gel containing either Picloram or Glyphosate
• Foliage spray when the plant is actively growing using 100ml glyphosate + 2ml penetrant/10L

Caution: When using any herbicide or pesticide PLEASE READ THE LABEL THOROUGHLY to ensure that all instructions and safety requirements are followed.