"Klara" wrote in message
...
In message ,
FarmI writes
"Klara" wrote in message
(snip)
I also saw some things that
say that gypsum only works with certain compositions of clay soil
(either
high calcium or low calcium or something like that but I can't remember
which, and on the wrong type it would make it worse!)"

Gypsum is calcium sulphate so adding it to high calcium soils just ads
more
calcium. The purpose of adding lime/gypsum/wood ash is to cause the clay
particles to flocculate and make the clay "fluffier" or more open to water
and roots being able to get through the pugginess (not very technical but
my
brain has gone to bed).

Add sand and sawdust and leaves and manure or anything that has has once
lived including old dead weeds, dead hens or old cotton Tshirts or green
manure crops. Tell her to not expect very much in the first year and even
if the veg she grows are pathetic, it will get better with each succeeding
year.

Thanks - as I said to Nick, the idea is raised beds on top of the sand and
soil, with all that you mention incorporated below a layer of topsoil,
with an eye to the long plan. In the first year I imagine each veg they
manage will cost an eye-watering amount ...



--
Klara, Gatwick basin

If the clay is that bad you cannot grow in it ,maybe you would be better off
digging the clay over,put deep raised beds over and fill with a good top
soil,then every year put a thick mulch on top and let it work in before you
start planting.The other option is to go for it on improving your clay with
organic matter,ie compost,manure and grit.Sharp sand maybe to fine be
careful what sand you buy if you go for the sand option.One thing you did
not mention was the size of plot we are talking about?
Cheers Keith
Nottingham