Giant Hogweed

Found widely in urban and rural areas across the UK, giant hogweed is classed as controlled waste under the Environmental Protection Act 1990 and therefore must be disposed of at a licensed landfill site. It is also illegal to plant or deliberately allow giant hogweed to spread in the UK. It colonises river banks where seeds are easily transported downstream.

Giant hogweed is a plant of the Apiaceae family which includes plants such as parsley, carrot, cumin, coriander, and parsnip. It forms a rosette of jagged, lobed leaves in the first year before growing a flower in the second year. Its stems are green with purple blotches and stiff, white hairs. Stems are hollow. Their leaves look a bit like rhubarb leaves, irregular and with very sharp edges. The underside of the leaf is hairy. Flowers appear in June and July. They are small and white or slightly pink and clustered together on formations known as umbels, which can reach a diameter of 60cm.

The sap of giant hogweed can cause burns because it contains a chemical which makes skin extremely sensitive to sunlight. Giant hogweed also has significant impact on on native flora, outcompeting species for resources and blocking out sunlight with its dense canopy. The lack of biodiversity alongside riverbanks results in soil erosion and lower water quality.

Biological analysis can help with identifying giant hogweed as it can often be confused with visually similar species such as common hogweed (Heracleum sphondylium) and cow parsley (Anthriscus sylvestris).

• To find out more information about removing Giant hogweed from land or ways of controlling it please see the government website: Gov UK – Preventing the spread of invasive non-native plants.
• Sample types include: leaves, stems, flowers and roots.
• It is important that samples are fresh due to fungal pathogens which may grow on dead plant material and be amplified during the PCR process. Therefore, please send samples to us as soon as possible, or freeze them immediately if you are intending to send samples in as a batch.
• *Sampling can be conducted using a biological collection kit or samples can be sent in in a sealed envelope/parcel without the use of a kit.*