One of our flower beds is a complete mess!!

Our garden was originally a field/paddock and we always have problems with
grass coming through in the beds but this particular bed has (IMO) got out
of hand. There are a lot of hardy geraniums in the bed and the grass comes
up through the centre and is impossible to dig out. In addition, in about
half the bed, the soil is rock hard (probably clay) and impossible to dig.

My thoughts are to start from scratch with at least half of the bed - i.e.
spray everything 2 or 3 times over the summer, then when everything has
(hopefully) died down rotavate the bed with a Mantis and leave bare over
winter with a view to starting afresh next year.

Am I doing the right rhing???

Jeanne