"tina" wrote in message
Should I use something like a couple of bags of FINNISH PLASTER,
that
contains GYPSUM to try and break it up a bit ?

The plan is its going to be a VEG PATCH.

We did watch the BBC prog about planning veg patches, but must admit
we had to laugh a bit when the lady said she had heavy clay soil,
which to us looked fantastic, think ours must be HEAVT HEAVY clay
:-)

Clay makes fanatastic veg beds as they are full of good minerals -
they just take a bit of work.

Add gypsum (aka Plaster of Paris) large quatnities of sand and work it
in then top the lot with lots and lots of manure (horse if you can get
it and don't worry if it's straight from the horse's arse -its
fabulaous stuff) and top that with hay/straw water and walk away from
it for at least a month but water if the weather gets dry.

Come spring, rake off the mulch and see what's happening below - if it
looks good (or better than what you started with) plant into it and
rake the mulch back round the plants as the soil warms up.

You may not get great crops in the first year but the idea is to breed
worms (my term for soil improvement as lots of worms indicates good
soil) but the goal is long term improvement and sand, gypsum and lots
of organic material will eventually give you that.