Xref: kermit uk.rec.gardening:158779

I wonder if anyone could help me. I am planning to build a patio with
a pergola over the top. The books I have seen recommend cementing the
upright posts for the pergola in the ground. I am planning to leave
'holes' in the patio to do this (perhaps cementing in the posts and
leaving space for some topsoil above it). The problem I think is that
the soil depth needed to support the root structure of say a clemetis,
might not be enough? Are there any other ways around this. I don't
really want to grow them from tubs or have the pergola structure
outside the footprint of the patio.

I would be grateful for any suggestions.

In article ,
(JonR) writes:
| I wonder if anyone could help me. I am planning to build a patio with
| a pergola over the top. The books I have seen recommend cementing the
| upright posts for the pergola in the ground. I am planning to leave
| 'holes' in the patio to do this (perhaps cementing in the posts and
| leaving space for some topsoil above it). The problem I think is that
| the soil depth needed to support the root structure of say a clemetis,
| might not be enough? Are there any other ways around this. I don't
| really want to grow them from tubs or have the pergola structure
| outside the footprint of the patio.

I strongly recommend NOT doing that. What heavy machinery are
you planning to install on your patio that you need an industrial
concrete base?

Yes, I really do mean that most of the books etc. on such things
seem to be written by the people who inhabit alt.pave.the.earth
(q.v.) rather than uk.rec.gardening :-(

I have done precisely that, and used NO concrete. My soil is
60% sand, which helps, because I didn't even need a base layer
and used just 2" of sand on compacted soil. On soils as stable
as mine, that will not shift in many decades with mere domestic
access. Similarly, the posts were embedded 3' into the ground
with NO concrete, though a small collar of concrete would reduce
the flex a little. They have been up a decade, including me (at
12-13 stone) climbing over them when pruning climbers.

If you INSIST on concreting over the earth, leave a 1' square
hold right down to the subsoil everywhere you might EVER want to
put a plant. A closed hole is nothing but a disaster, because
it will fill with water in wet weather and dessicate in drought.
And that applies whether it is a 6" cube or a 6' cube.

Incidentally, the place that you put concrete around a post is
just below soil level - there is no point in concreting in the
post at the bottom.


Regards,
Nick Maclaren.