[H]omer wrote:
Nick Maclaren wrote:
In article , [H]omer
wrote:

So you reckon 12" of chips followed by 6" of organic material?

6" doesn't sound very deep. I was planning on planting trees as
well.

Is that really all I need?

Most clays are very fertile - all they need is to be opened up
so that water can drain and air reach the roots. So you don't
want to remove the clay so much as dilute it in the soil with
coarse material. This needs to be done fairly deeply, for the
drainage.

6" of organic matter is far more than most soils have. My loam
has 12-18" of topsoil, of which only a small proportion is
actually
organic material, and it is nearly as fertile as soils get.

I didn't make it clear before, but my current 'soil' is about 1/2"
of
what looks like mainly sand (think the kind of soil you get at the
inland edge of a beach), followed by ???" of clay (I haven't struck
rock yet!!!). Therefore, for all intents and purposes, there is no
real soil on site; I'll have to buy some in.

/me gets his calculator out

Is this about right then? ...

I excavate 24", and keep the clay.
I mix the clay with aggregate, and backfill 12".
I buy in a skip of topsoil, and backfill 6"
I buy in a skip of GP compost, and backfill the remaining 6"

Does that look OK?

I wouldn't bother buying in the compost: the topsoil you buy probably
won't be brilliant, but it'll do perfectly well; and compost alone
won't provide enough physical support for plants (remember it's used
in pots and other containers, not the open ground). I reckon the
stone underneath should give you reasonable drainage, as long as the
water's got somewhere to _go_. If there's no way out, all your
operations won't have any long-term effect. So if you're going to dig
out, it would be worth putting in some plastic land drains (local
farmer's merchants or Jewson-type place). But of course, they'll
still have to lead somewhere.

I think I'd let it all settle for a year before putting in trees: it
won't be very stable. (I have to say it's amazing what will survive
in almost pure clay; and of course growing things will improve the
soil in itself.)

--
Mike.