sallyg said: If the species I am familiar with, we used to have some volunteer every year. I think they were pale pink like this. And fun to pop!
purpleinopp said: That is so pretty! I wonder if it might be this one?
Himalayan Balsam (Impatiens glandulifera)
The blooms don't look like a match for I. balsamina, or the usual walleriana or hawkeri one might see @ a store.