"Mike Lyle" wrote in message
...
KD wrote:
Hi all,
After a couple of years with just turf, me and the Mrs are trying to
get into a bit of gardening. The problem is our house and garden are
built on an old spoil heap. The soil is typically clay and extremely
black (i.e. coal slag) below about 7". We've started proactively
adding compost, sand and organic matter to the 'soil' before thinking
of planting, to improve our situation. Are there any other tricks
that you can recommend to make this a decent place to grow 'things'
or are am I being too pessimistic about our chances ?
All suggestions gratefully received. For climate purposes we are
just south of Edinburgh, if that has any bearing on things.


I'm talking theoretically, as I haven't done it. I have done several
years' gardening on a very thin soil layer, though, and had no serious
problems.

You're doing all the right things. I'd carry on adding all the good
stuff you can get, and avoid digging too deep. I speculate that the
underlying spoil will improve your drainage, and that if a bit of it
gets among the clay top layer it could help by darkening the soil and
encouraging it to warm up in spring.

The only worry might be that there could be a high sulphur content in
your spoil layer, but if things grow that won't matter a bit. If plants
start looking funny, I'd suspect a mineral imbalance, but we can cross
that bridge if we get to it.

--
Mike.


Cheers Mike. I'll continue with what I'm doing but I'll not dig down enough
to reach the original mine shafts :O)
You've made me feel a little more optimistic.

Thanks,
Keith