"Paul" wrote...
I read that for broad beans you should dig the roots into the ground
(something about nitrogen?). Does this apply to runner beans too?

The problem with Runner Beans is that the roots are large and woody so don't
break up easily, and as they are also perennial they will regrow from the
roots after a mild winter. Been there done that.

--
Regards
Bob Hobden
just W. of London