In article ,
Jeff Layman wrote:

If your soil is even half-decent, it will grow perfectly well. That's
required only for clay and other unsuitable soils - at least most
clematis like good drainage, a deep root-run and reasonably fertile
soil.

Thanks all - it _is_ clay... I'll dig deep. It can have some of the
not-yet-rotted-properly stuff from the Dalek in the bottom.

That's a good idea. If you have any surplus rubble, that could go
in right at the bottom.

You're kidding aren't you?

As it happens I'm digging up what appears to be the foundations of the
old outside toilet, and have several hundredweight of flints. That's the
explanation for why one of our flower beds has always had poor drainage!

No, I am not. Foundations are almost always made fairly solid, and it
is rubble with air gaps that drains well. Eventually, the soil will
percolate to fill up the air gaps, and that will stop working, but it
takes a very long time for a decent thickness of rubble.

Not necessarily, particularly with heavy clay soil. Dig a hole in heavy
clay, leave it, and after heavy rain (remember what that is?) it will
fill with water as the hole acts as a sump. Rubble will make little, if
any, difference.

That is true but, in that case, digging a deep hole is pointless, no
matter WHAT you put into the hole - so there's no point in wasting
compost in it.

I doubt many clematis will complain about being too wet - more likely
the opposite - but like many plants won't put up with living in a pond
for any great length of time. In that sort of ground, I would make a
raised mound and put the clematis in that if there was no alternative
position for it.

Actually, no. I have lost several clematis for that reason, and my
soil is 60% fine sand. Our native clematis thrives on chalk downs,
where there can be no water for many feet down in dry spells, and
at least some others live in similar conditions. But I agree that
clematis vary and some might be able to tolerate wet conditions.

The other option for such conditions and plants that hate waterlogging
is a pot or tub with the bottom knocked out, embedded an inch or two
into the ground.


Regards,
Nick Maclaren.