On Sun, 26 Aug 2012 15:27:11 +0100, Another John
wrote:

I'm doing some gardening for a friend. She has raised beds (brick
walls about 30" high). She's complaining about the quality of the soil
in the beds, wants me to remove all plants, dig in "soil improver", and
replace selected plants.

The soil is black and fine, but seems very "heavy" -- perhaps "dense" is
a better word. I'm wondering if it's the type of stuff excavated from
river basins and sold as topsoil: it's a bit like the silt you'll find
beside a river. Naturally my first thought was simply to get bags
of compost and dig it in, but I'm aware that these days there are
several kinds of "soil improver" on the market, so I'd prefer to get
some advice first: I'll need a dozen or more bags to improve the top 6"
of the total area.


By the way, I've haven't done a Ph test, and cannot at the moment
because the job is in another town, about 150 miles away.

TIA for any comments,
John

Black soil tends to be high in organic matter/humus and so is quite
rich in nutrients to begin with. But it can also contain a lot of
other things and when you say fine but heavy, that may indicate a lot
of clay content.

So in addition to the pH test that Baz recommends - and this will be
an essential pre-requisite to any recommendation as to what to add to
the soil - you need to establish the type of soil. For example, when
wet, if you get a handful and squeeze it, does it stick together like
a muddy ball or does it remain crumbly? If you poor water on it, does
the water drain through or puddle on the top? When it gets dry (as if,
this year) does it set solid and crack or remain malleable?

A little bit more info is needed if you want constructive suggestions;
otherwise all we can offer is best guesses.

Cheers, Jake
=======================================
Urgling from the East End of Swansea Bay where sometimes
it's raining and sometimes it's not.