Giant Hogweed

Also known as:
Wild Rhubarb, Cartwheel Flower, Wild Parsnip, Cow Parsnip

General description

Perennial to 4-6 m tall. Has stout dark-reddish-purple stems, and spotted leaf stalks with sturdy pustulate bristles with a toxic sap. Stems and stalks hollow, stems 5-10 cm diameter. Large leaves (up to 1.5 m) and tuberous root stalks. Large umbrella-like clusters of greenish-white flowers.

It usually grows on the banks of rivers or creeks and gardens.

Out competes and replaces native plants. Very poisonous to humans. Touching it, or exposure to dust from weed-eating, can irritate skin and cause blisters and swelling. The toxin causes photosensitisation- skin reacts badly to sunlight.

Site management

Recommended approaches

1. Plants may be dug-out, care should be taken to remove the majority of the root stalk to prevent regrowth.

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

Similar species

Chilean rhubarb
Gunnera tinctoria

Chilean rhubarb's leaves are less deeply lobed. It forms tiny green flowers on a spike.

RPMS status

Surveillance - Whole Region
National Pest Plant Accord species - nationwide
giant hogweed - Main species image