I cheated by (deeply) forking over the first bit of the bed. That seemed to be ok at fishing out weeds but couch grass appeared like exploding spaghetti in the rest so deep digging was called for. Dig, fish out handful of roots, turn soil, pick out the bits you didn't see first time. Repeat till end of row.Fork bottom of trench.goto 10. One dustbin and two trugs of weeds, carpet amd crap later the top quarter of the bed is done. It's a bit higher than the rest but needs leveling so it will come out roughly flat.
I'm concerned that I've left some fragments of couch grass in there. Time will tell, I'll spot weed with fork or roundup later in the year if weeds come up.
Garlic and white onions in, reds and shallots to go in next weekend, leaving about one row for leeks later in the spring
Not sure about the rest of the bed yet. Too square for the amount of broad beans or peas I want to plant.