On 23/10/16 21:16, Vir Campestris wrote:
Many years ago someone put a shrubbery in our garden. It had weed
control fabric, and I suspect a layer of bark chipping over the top.

I've just moved one of the shrubs - it is now overshadowed.

The bark mulch has mixed with many years of leaves to make a couple of
inches of quite nice compost. The shrubs have spotted this, and put
roots in it. There are also a variety of smaller plants growing in it.

Underneath the fabric the ground is clay. It's had no worm activity in
years, and has set to a hard pan similar to subsoil.

It took me nearly an hour to dig out one small shrub (roots 50cm across,
20cm deep) followed by having to tease out the weed control fabric
layer. It's no longer completely root proof, and there are some roots
going through it.

Andy

Yes, WCF is a bit of a love-hate affair. When we moved in, most of the
borders here (and for some reason, the ground under poorly-laid
paving), was covered with WCF. That was then covered with a mulch of 20
- 40mm pebbles, to a depth of 50 mm or so. Well, it was very good at
stopping the umpteen thousand ash seedlings from getting their roots down.

But adding shrubs and other plants has been a bit of a problem. As you
say, the ground is pretty hard under the fabric (we are on clay). The
worst area was a dog exercise area just outside the patio. This was 7 x
6m, and had the original "builder's top quality soil" under the fabric.
Some of it was clearly an old path, with a covering of what looked like
compressed old railway line ballast, then the fabric, then the pebbles!
Add to that 20 years of collies running up and down on it, and not much
was going to grow in that! The patio and a couple of metres of the
pebbles went when we had a conservatory built, but what to do with the rest?

The simplest thing was to turn it into a Mediterranean garden. I removed
a small area of pebbles, cut through the fabric in an "X" big enough for
the plant, peeled the membrane back, and used a ground-breaking spike to
get into the ballast and clay (very hard work!). When the hole was big
enough, in went a layer or grit, then decent compost with gritty washed
sand included, and the plant put in that mix. The fabric "X" was
replaced up to the stem of the plant, then the pebbles, and the whole
lot watered well. Apart from a rosemary which died in a few months (no
idea why), everything else has grown like mad, despite earthworms being
almost absent. I was a bit concerned that the holes I dug would act like
sumps, but that hasn't been the case.

--

Jeff