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I am preparing a very hot, very dry area of my garden to become a scree garden. It will have a weed supressing blanket and the 5+ cms of small shards of slate. On top will be three very large planters with phormiums.

The ground previously had some shrubs, brambles and a few blackthorn growing in it. I have removed all the vegetation and dug out almost all the roots, only leaving small, thread like roots.


I have attempted to buy caustic soda to "sterilise" the soil before putting down the weed blanket but I have been told that the use of caustic soda is now banned here in France. I have been offered glyphosphate but it seems to me that this would be pointless on bare soil.


Suggestions, please.


  • Not sure what you are asking here. You have cleared the ground, dug out the weeds and have planned how you are going to cover and fill the area...all sounds that you are doing the right things in the right order and making a good job of it.

    As you also say, glysophate is no good on bare soil but if any weeds do reappear next year you have the glysophate to zap them when they are in good growth.

    You seem to have answered your own question - I think - or have I missed something ? image

  • WelshonionWelshonion Posts: 3,114

    Bit worried that you would even suggest putting caustic soda down.  Isn't that for drain clearing?  Did you mean sodium chlorate, which is banned?

    Otherwise you seem to be going down the right lines.  Make sure the weed supressing membrane is a heavyweight one if you want it to be permanent.

    This is purely personal, but I don't like phormiums, but in your situation they may look fine.

  • GillyLGillyL Posts: 1,077

    Are you asking for suggestions for more plants?

  • waterbuttswaterbutts Posts: 1,214

    Why do you feel the need to treat the soil beneath the weed suppressing fabric and the layer of shale with anything at all?

    There are very few pernicious weeds that could fight their way through that lot.

  • sodium hydroxide or caustic soda would kill all remaining weed seeds and any viable roots but as I cannot buy it I want to use something to ensure a belt and braces job.

    I am happy with my planting scheme, having purchased the planters and the plants already. Phormiums were chosen as the site is very, very hot and closed on two sides by one, the house with white walls and secondly by a white wall one and a half metres high beside the swimming pool. the site is otherwise closed by a concrete. and stone patio. It is some distance from any other planting and so I am not concerned about anything leeching from the site.

    The weed blanket i have bought is dense and of good quality, it will be doubled in several places.

    It seems as if the advice is not to bother with any additional soil treatment


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