Pig's ear

Cotyledon orbiculata

Also known as: Round-leafed naval wort, elk horn
Pest group: Plants
Pest type: Succulents

Pig's ear is a succulent with a clump-forming sub-shrub standing less than a metre tall. It displaces native vegetation.


  • Leaves are grey-green with red margins.
  • Flowers are bell-shaped and can be orange, red, or pink and borne on stems less than 50cm tall from December to June.
  • Seeds dispersed by wind and gravity. Vegetative spread from fragments.
  • Habitats include coastal cliffs, rocky outcrops, banks, dunes, scrub, grasslands, and pastures.

What you need to know

Displaces native coastal vegetation. Can form dense clumps in coastal ecosystems.

Management approach

Pig's ear is an unwanted organism regulated under the National Plant Pest Accord.

National Pest Plant Accord (NPPA)

The NPPA prevents the sale, distribution and propagation of specified pest plants within Aotearoa/New Zealand and is administered by the Ministry for Primary Industries (MPI).


Any species declared a pest, including unwanted organisms, cannot be sold or be in a place where plants are being sold. Pest plants cannot be propagated, bred, multiplied, communicated, released, caused to be released, or otherwise spread.

See the MPI website for more information on the NPPA.

If you see pig’s ear, we want to hear about it. Please report your sighting, and attach a photo for our team.


Site management

Follow up treated areas three times per year. Encourage natural regeneration of native plants or replant treated areas where possible after two to three treatments to establish dense ground cover and minimise reinvasion.

Physical control

Dig out.

Plant parts requiring disposal: All parts.

Small amounts can be rotted in a covered water barrel or contact your local council for appropriate disposal locations.

Chemical control

Basic Growsafe certified: For small infestations, use foliar spray with 3g metsulfuron-methyl plus 150ml glyphosate per 10L of water.

Certified handler/experienced agrichemical user: For medium to large infestations, use foliar spray with 3g metsulfuron-methyl plus 150ml glyphosate per 10L of water and 10ml penetrant.

Caution: When using any herbicide or pesticide please read the label thoroughly to ensure that all instructions and safety requirements are followed.

Biological control

Biological control is not currently available for this species.