Despite prolonged efforts to weed out giant hogweed, more finding places are reported every year in Estonia.
It looks as if Estonia is fighting a losing battle. A single head can produce up to 2,000 seeds and if these hit the ground, the situation is much worse come next year, Maria Rätsep, and environmental protection expert in the Environment Board, told Postimees.
The seeds are resistant and may stay in the soil for five years or more. Hence, with large colonies, it takes years to get any result.
Giant hogweed is a mighty and easily noticeable plant that usually grows 5-6 meters high, although a 7-meter tall specimen has been reported from Jõgeva County.
Giant hogweed and Sosnowsky's hogweed are foreign plants in Estonia that pose a threat to the balance of the local ecosystem by replacing native species. With their massive leaves they leave smaller plants in the shade, forcing them to die and so reducing diversity in natural habitats.
Both plants are also phototoxic and thus pose a threat to humans. People who come to contact with their sap and are then exposed to sunlight, usually develop severe and painful skin inflammations, blisters and even ulcers within 48-72 hours.
Editor: M. Oll