What does giant hogweed look like?
• Giant hogweed is an erect perennial (long-lived) herb which is distinguished by its size; the weed can grow to 3.5 metres when in flower, but can sometimes reach 7 metres in height. The stems are stout, hollow, with purple blotches. The leaves are large and deeply incised, resembling rhubarb leaves, and may grow to more than a metre in breadth. The undersides of the leaves are densely hairy. The flowers occur in broad, flat topped flower heads, and produce large dry fruits. The roots are tuberous and spreading and give rise to new buds each year. • Giant hogweed produces the first flowering stalk in its third, fourth or fifth year. After setting seed over summer, the plant dies in the following autumn. • Spread is by seed, and by buds formed on the crown and tuberous roots. Seed is spread by moving water, birds, and via the ornamental plant trade, dumping of garden waste and the spice trade. Image top right: Flowering stalk of Giant Hogweed, photo: Leslie J Mehrhoff. Image above: Gia
