Is there a way to tell the difference between Geum avens (the one that is a weed) and Geum rivale( the pretty ornamental one) before they flower?
Do you mean Geum urbanum, commonly known as Herb Bennet? This can be a real nuisance in the wrong place and is difficult to identify before the flowers appear. Usually it will pull out more readily than the G. Avens, but if in doubt, wait for the flowers and get it out before it goes to seed!
A gardener's work is never at an end - (John Evelyn 1620-1706)