Posted: 29/04/2017 at 16:15
That looks like Himalayan Balsam. It's invasive and it's illegal to plant it in the wild as it is damaging our riverbanks. It has pink flowers and catapults it's seeds huge distances. However, it's pretty easy to get rid of if you pull it up every spring before it flowers and seeds ... the seedlings are pretty easy to identify and not difficult to pull up.
Where we lived once before, a neighbour used to grow it and it spread all over the place and into our garden, but his landlord sprayed his garden to get rid of it and the rest of us pulled up whatever appeared in our gardens, and now it's gone.