In article , H
writes
cover it in black polythene/carpet/cardboard and stand well back for a
year.

Not an option I'm afraid. I don't have a year to sit back and wait......

I could dig out the beds and lay everything else down to
polythene/carpet/cardboard I guess.

You could cover everything and cut holes for plants and slits for seed
drills. I've never tried this, mind!
--
Kay Easton

Edward's earthworm page:
http://www.scarboro.demon.co.uk/garden/