On 12/05/2015 08:23, Martin wrote:

It grows between paving stones in The Netherlands. Under the paving stones is
sand, all the way down. The local authorities controlled Horse Tails by spraying
pavements with glyphosate. This now banned, mainly because local authorities
sometimes sprayed just before rain. When it rained during or just after
application, the glyphosate didn't have time to break down and it ended up in
the ground water.

It seems to prefer a sandy soil. Everywhere I have seen it as a serious
pernicious weed has been on sandstone and lighter clay soils.

Glyphosate spray on its own will not get anywhere near it. The stuff has
a silicon dioxide surface exoskeleton that is so hydrophobic that like
holly and ivy weedkiller never touches the plant surface and has little
or no effect. You have to bruise the stems first (or use insanely high
doses of glyphosate which is not a good idea in spray).

Gel formulation DIY using wallpaper paste is one way that delivers it.

--
Regards,
Martin Brown