In article ,
writes
http://garden.fotopic.net/p12901226.html

Can someone please identify the unknown plant in the middle for me,
before my brain explodes with the effort ? I know it's going to be
something quite common, probably, but I cannot remember what it is (I
planted the damn thing too!). Thank you to anyone who knows and posts.

Hi

I'm probably wrong but it almost looks like a verbena bonariensis in a
white form - can't be that sure though!

Lynda