Thanks so much for all your advice.
When we cleared the ground in the autumn (with machinery that compacted the soil a bit, though left good furrows for planting), I had hoped to be able to seed with green manure to help keep existing weeds at bay as well as build soil structure before weeds took hold once more. I also thought this mix would be attractive to look at while I am deciding how to design and lay out the space. We were too busy with other jobs, clrearing and grass seeding elsewhere, so missed the best time.
Now with our mild climate down here the weeds and grasses are back – perennial ones seem to be dock, thistles, nettles. Couldn’t see any couch and it is too early for bindweed. The land is adjacent to pasture and would have been taken from grazing pasture land. I don’t want the weeds to reclaim their former majestic ground while I am planning !
So I guess I will need to mulch or polythene before sowing the green manure.
Despite the expense of municipal compost, I am guessing that it would be less work to mulch with compost, sow green manure, wait 12 months plus (the seed mix is designed for 12 months minimum), then compost again before sowing eventual crops? Alternatively I would have to buy polythene, lay it, and work the soil before sowing green manure?
Thanks so much all