On 21/06/2019 10:17, Roger Mills wrote:
I have a patio area/path consisting of a couple of inches of pea gravel
on top of some weed matting.

When I first created this 20-odd years ago, I gave the soil a liberal
dose of sodium chlorate before laying the weed matting. This kept it
weed-free for quite a few years, but the matting has now deteriorated -
allowing a lot of weeds to take root.


Matting is pointless . Weeds do not grow up from underneath after the
initial laying. They get carried in along with soil in the wind and
rain., And on the cars if its a drive


I have removed the gravel and the weeds, and am about to take up the
matting and renew it before covering it with new gravel. I need to be
able to neutralise the soil in order to prevent any roots or seeds left
in from growing. I don't think you can buy sodium chlorate any more.
Most of the weedkillers available seem to be of the systemic type -
which kill existing weeds but don't affect the soil. But that's not what
I want!

Any bright ideas?

you can make sodium chlorate by boiling sodium hypochlorite aka bleach


I agree is is the best 'desert storm' type 'kill everything forever'
weedkiller

But I think the answer is to regard gravel as not that permanent - I am
redoing mine after about 16 yeas - its very bad where cars have dropped
mud, OK in places where it was deep and cars haven't been.

And thats the point. What caused the weeds is nothing to do with
membranes. It is soil etc carried onto the gravel where it forms a great
place for windblown weedseeds to get their feet down. That soil wont be
chlorated so it wont stope the weeds. Alll that works is removing the
weeds and the soil with them and regular 'path clear' or chorate


I am going to try sieving the soil out & removing the weeds washing and
and reusing it. Gravel is expensive. And so are minidiggers

My drive is in total about 30 tonnes worth




--
€œBut what a weak barrier is truth when it stands in the way of an
hypothesis!€�

Mary Wollstonecraft