Although it closely resembles harmless cow parsley and our native (and harmless) common hogweed, don't let its pretty flower-like appearance throw you off. This dark-green giant contains sap that can burn skin when exposed to sunshine. It can keep causing skin issues for months afterwards. Please don't ever touch this plant.
Due to its height, giant hogweed keeps other plants in the shade, preventing the sunlight from reaching them. This increases the risk of bank erosion when the weed dies off in the winter, exposing bare banks where other plants would normally grow.
We try to prevent giant hogweed growing on our waterways where people can come into contact with it. However, this is a tricky task as each plant can produce over 10,000 seeds that float down waterways. We spend nearly £100,000 per year controlling giant hogweed and Japanese knotweed.
Report a sighting
Please let us know if you spot giant hogweed on our canals and rivers. Find our contact details here