Giant Hogweed

Giant HOgweed

Origin: Caucasus Mountains

UK Distribution: Widespread

Habitat: Most common on river banks but can grow almost anywhere

How was it introduced? Introduced as an ornamental plant in the 19th century

How does it reproduce? Spreads by seed dispersed along water corridors and by the wind

Sometimes, INNS are referred to as “alien species” and giant hogweed is one INNS that truly looks to be from another planet. This triffid can grow up to 5 m tall, with flower heads spanning 80 cm across and leave up to 1 m in diameter!

Giant hogweed is a risk to human health. The plant produces a toxic sap which can react with skin and cause severe chemical burns under UV light. With this in mind, if you think you spot a giant hogweed plant, please stay well away and report it as soon as possible.

As well as the danger posed to us, giant hogweed forms dense stands which out compete and out shade native plant with its towering size.

Wandle distribution: Giant hogweed can be found in Sutton, Merton and Wandsworth in small local patches meaning that control and eradication is a strong possibility. Our Invasive Species Officer has removed 180 giant hogweed plants in the last year, and thanks to our trained River Rangers, he knows where to look next for more plants to tackle.

Think you have giant hogweed on your land? If you think you may have hogweed on your land, please take a picture and send it to us at We can ID the plant and then provide you with guidance on how to control this species.