Hello, Eliza. Besides the poisonous aspect of Giant Hogweed, it is a very invasive plant ("flower heads which can each produce about 50,000 seeds every year..." according to the following link.) In parts of England at least, removal of identified plants appears to be underway. http://www.bbc.co.uk/news/uk-england-leeds-13929473

There are many introduced plant species I welcome, others I can deal with. Giant Hogweed is one I would destroy because of its longterm damage potential to people, the extraordinarily high germination rate, and the longevity of its seeds. Eradication challenges are discussed in this PDF document

Regards,

Maeve