Robert,
i've been doing a bit of research , takling around and also thinking things through ( all quite unusual??
)
I suspect the moss arrived when the top growth gave it ideal shelter and moisture conditions . Killing off the crud with round-up just exposed it and my clawing out the dead stuff just made it look worse.
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Apparently the top soil that was used to fill the gardens front and rear after the place was built 33yrears ago came from near the pit head of a defunct now demolished coal mine according to one local old boy across the road .
It has never been cultivated except by me so the soil will still have a high sulphur content despite me wacking in tonnes of well rotted stable muck that has straw in it along with about three tonnes of it that has wood pulp chip instead of straw.
Yes the soil is now quite crumbly from the manure & wood pulp/chip but the manures will also have added to the acidity of the sulphur content and apparently that why the moss has thrived and taken over .
I've put almost half a 25 kg sack £10 at of so called garden lime a couple four days ago ..... ( fine sand and crushed limestone ) on the beds then watered it in and got a two shot soil test kit so I can se what is what in another 26 days time.
I'll be getting a bag of builder lime this time though ,no more of this lawn sand stuff .
Now four days after liming the moss is starting to look as though it is being killed off and has started to take on a yellowish tinge.