GardenBanter.co.uk - View Single Post

19-07-2006, 02:05 PM posted to uk.rec.gardening

wrote:
John Kelly wrote:
Anyway - I'm doing a lawn. The level of the ground needs to be raised so
I'm going to need to buy topsoil. The problem I have is the condition of
the existing ground. It was recently a building site and is basically
hardcore stones and rubble with a fair amount of sand and poor quality
soil. What depth of good quality topsoil should I use for planting
grass? I don't need a bowling green type lawn but I don't want one which
is patchy either.

What you have should provide some drainage, although I would remove the
larger lumps of concrete etc. first as they will cause brown spots even
2 foot down - think about crop marks and arechaeologists. If you work
some (lots of) humus into what you have and rotovate it in then it will
improve water retention in dry spells. It will also make what you have
far more useful. It is important that the base is as evenly mixed as
possible, you can't just throw a blanket of goodness over badness and
expect the badness not to come through. Think sheets and matresses.
Then I reckon a minimum of 4 inches of resonable quality loam,
depending on the type of mix you will be sowing.

You need to interpret the site: low lying and boggy will need improved
drainage, while arid will need the water retention improving with
(potentially huge) amounts of rotted vegetation. Think riding school
waste.

All the advice you've been given is textbook-quality. But even four
inches of bought-in topsoil is an expensive item. If curtains and
things are more important in the budget, as they so often are when
one's just moving in, I'd be quite happy to skimp. There's no soil so
bad that it can't be turned into good soil. Certainly get the biggest
lumps out, until you get bored with it, but don't worry too much about
archaeological air photos: the point about that is that the effect is
generally invisible _except_ from the air and when the light is right.
It's possible that you don't fly over your lawn as often as some people
do.

It really is surprising how well an awful soil will grow things, so I'd
buy in what seems like an affordable quantity of council compost and
work it in. If after that you still have a lot of satsuma-sized stones
at the surface, it's probably time to think about a load of topsoil.

Don't use a rotovator if it's full of stones, of course. On the whole,
I tend to say "don't use a rotovator at all". They don't really belong
in the small private garden, unless you enjoy machinery for its own
sake -- and I've got nothing against fun. Fork and rake are less aggro,
and let you feel any nasties you'd rather not disturb.

--
Mike.