On Apr 13, 8:55 am, Klara wrote:
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 ...

Not if they just grow spuds and other tough crops to start breaking up
the ground for this year. The soil has to be solid brickworks clay
before they will fail to make a decent crop. Various fruit bushes and
rhubarb will grow OK in heavy clay so only improve the soil where you
want to grow tricky things needing good drainage.

Clay soils are actually very fertile - just a bit inclined to be too
wet in winter and rock hard in summer.

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

The clay isn't solid, it would probably be possible to dig it and plant
in it, but they want to start improving it as much as possible straight
away. The whole eventual area must be about 5m x 15m, but they are
planning to start with just two raised beds maybe 1m x 3m and gradually
work their way over the garden. (Like everybody else, work and commute
takes too many hours, so it's weekends only.)

Are we overestimating the quantity of sand they need at this stage?

If you are determined to do it this way then try a 1T bag of sharp
sand and work it in. But if you obtained the same amount of spent
mushroom compost or well rotted compost the worms would mix it in for
you.

Like Nick I reckon adding sand to clay soils is vastly overrated. And
proprietory clay flocculators are a total waste of time. You would do
far better adding some organic bulk to the top as a mulch. So much
better if you have a compost heap for all your own grass cuttings and/
or can buy in cheap council well rotted recycled green waste.

If the clay isn't solid I would be tempted to grow the crops that will
tolerate such conditions until the soil improves rather than spend a
lit of time and money on it up front. That has always been my
solution. YMMV.

Regards,
Martin Brown