On 26/05/2015 16:02, Chris J Dixon wrote:
john west wrote:

Am trying to get into shape a garden containing some quite hard (but
seemingly good) top soil, but it has quite a lot of lumps of clay in it
(dug up from the clay bed from about a foot below) some time in the past.

I have some ready access to a endless supply of rotted leaf mold heaped
up from somewhere nearby and similarly a lot of old lawn grass cuttings.

With the intention of growing just flowers and shrubs (no veggies) in
the garden, should i try to remove all the lumps of clay ( a lot of them
are only a couple of cm across) ?

Whilst you are at it, gypsum is recommended as a soil improver
where clay is present, but appears to be sold in garden centres
as a proprietary product costing over £6 for 2.5 kg.

http://www.capitalgardens.co.uk/clay...er-p-6321.html

On the other hand, I picked up a 25 kg bag of multi-finish
plaster for under £5, and AFAIK this is essentially the same
material. It worked very well.

Chris


I don't think gypsum sets when mixed with water, but probably not
important in the long term