Common name: | Giant Hogweed (also known as Wild rhubarb, cartwheel flower, wild parsnip) |
Scientific name: | Heracleum mantegazzianum |
Management programme: | Organism of Interest (OOI) |
Giant hogweed is poisonous to humans and care should be taken when removing this plant. Exposure to dust or sap can cause skin irritation, blistering, swelling, and long-term scaring. If a person gets the sap in their eyes, it can cause temporary or permanent blindness.
This perennial herb (plant with a life cycle of three or more years) can form dense colonies that suppress native vegetation. When it dies down during winter, it can leave infested banks bare of vegetation and susceptible to erosion or reinvasion by other pest species.
Giant hogweed has been recorded in coastal Otago from Oamaru to the Catlins and in Central Otago:
Between December and February is the best time to spot giant hogweed as it is flowering and fruiting.
There are no specific rules associated with Giant Hogweed as it is an Organism of Interest in the Otago Regional Council’s Regional Pest Management Plan (2019-2029).
Giant Hogweed is declared an Unwanted Organism in the National Pest Plant Accord . This means it cannot be sold or be in a place where plants are being sold. It cannot be propagated, bred, multiplied, communicated, released, caused to be released, or otherwise spread.
TAKE GREAT CARE!
Wear protective gear to cover your arms, hands and eyes. If you get the dust or sap on your skin, wash the area immediately.
Physical control:
Chemical control:
Be aware, seeds can remain dormant for up to 5 years. To effectively control this pest, continue to monitor the site and consider planting native species, as these can prevent giant hogweed from growing back again. To find native planting advice visit Otago Native Planting Guide.
There is no programme in place for an Organism of Interest (OOI), but they are watch-listed.
Any plant listed on the NPPA is an unwanted organism under the Biosecurity Act 1993. This means they cannot be distributed or sold in New Zealand.