Its a prolific seeder, its also a biennial, if you can get rid of it before it flowers, you maybe on to a winner

Agree!

Thanks, I think I may have lost the battle but will keep trying.

I don't get rid of mine. I think it's a lovely little plant, and as I grow wild plants as well as cultivated, it doesn't matter too much. Just dig out the ones you want to get rid of before flowering, as Dido says. It's actually a wild geranium, and the bees like it, so it would help pollination in your garden to leave a few in there. Mine are growing round my wildlife pond, so they don't look out of place. The flowers are beautiful and the leaves turn a lovely red colour after flowering. They look really attractive growing amongst other plants. I must like them much more than you, Flintstone. Happy weeding! Annie(Cumbria)