"Me-G" wrote

My garden has seen a lot of trampling by tradesmen over the past few
years. Retaining walls were destroyed, weeds, especially docks
flourished and, it seems, all draining material was washed away. The
garden is like a solid mass of clay.

Those responsible have agreed to "sort" the problem. They did dig it ov
er but the first heavy rain flattened it leaving puddles which didn't
drain for ages but did wash teh earth onto my paths: yewk: constant
cleaning and, as clay sticky so perpetually dragged through house.

They said they'd sort the drainage problem by digging in course sand.
However, I read somewhere that this would only serve to turn the clay to
a cement. It suggested that loam would also need to be incorporated
with the sand.

Can anyone advise on this?

The other matter is that they say they can't do that work just now as
it's a job for the Spring. Problem I see is that I will want it ready
for planting in Spring and given the lack of speed with which they work,
they could well call Summer, Spring. How early, ground being
sufficiently soft for digging of course, can I stipulate as a last date
for fixing.

I would have thought we'd want the last frosts to help break up the
earth to further help with drainage.

(Not really confident about using capitals at season names: dyslexia
rules KO!.)

All help on these matters gratefully received and much appreciated.

I have gardened on nice fertile clay for years on our allotments and you
have to be very careful when you work it, moisture wise, and never stand on
it without walking boards. Dug at the wrong time and it will ball up, bake
hard in summer, and take years to get any structure back. Don't dig when wet
can't dig when dry!
Gypsum will break up clay allowing it to be worked, sand and humus to be
incorporated etc, but it's not a permanent fix
Spring should be good provided it's drained by then, sharp sand or grit well
rotovated in will help drainage and one of our plot holders has used it on
his large plot to good effect although he has to water considerably more in
a dry summer. Humus worked in at the right time is best but it has to be
done often.
Most plants don't mind clay soil BT, but if you want a lawn then you will
certainly need to get the drainage right now.
Do check the pH too, clay can be quite acidic.
--
Regards
Bob Hobden
W.of London. UK