The Natural Philosopher wrote:
Fitting a membrane will hold the water in and encourage them to
germinate.

I've not used / tried such yet but I thought the *point* of these
'membranes' is that they are permeable?

Only time Ive seen them work is on top of the soil: Once the dirt
collects the grass starts a-growin.

We've got them with bark/slabs on top. Weeds root in the bark but pull
straight up intact with no effort, unless they've managed to slip a root
under the slabs.

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