"Bruce Ella" wrote in message
...
I am trying to convert an area previously covered by shingle into grass
with
a flower bed on either side. after digging up the shingle I discovered
hard
clay, with large large pebbles underneath. I have turned much of this,
and
removed much of the stones. I have been trying to improve the quality of
the soil, so that the flower bed would be useable by adding multi purpose
compost. I have read that adding gypsum helps to soften/ break up the
clay. When I went to Wickes to get this they look at me blankly.... can I
just but 'finishing plaster' or does this have cement in it already?

Multi purpose compost can be used as a soil improver but it would be better
to use:

Ideas to improve the soil: horticultural grit, vitax clay breaker or
organic matter (eg composted horse manure)