In article ,
Anne Welsh Jackson wrote:
"Vipera berus" wrote:


Cheap thin bleach (Sainsbury's 20p or so...) Neat with a stiff brush, lasts
for ages!

It will, of course, kill any plants if it lands on the garden, or even if
it washes onto the garden after rain...

Not seriously. It degrades rapidly on contact with organic material,
so will kill only the plant parts immediate adjacent to the slabs.
Most established plants will not suffer badly, unless you go mad
with it.


Regards,
Nick Maclaren.