Just found this:
"Horse or Mares Tail
Horse or Mares Tail, Equisetum Arvense is, in my opinion, public enemy
number one. It looks like it belongs in Jurassic Park and, unchecked,
spreads like wildfire.
In spring, brown green shoots appear with small cones at the tips that
produce spores. (Arghh * millions of Œem) and it grows away from creeping
thin brown roots that you can hardly see as they are soil coloured. Digging
out these roots is not feasible * they go down into the soil for up to 1.5
metres * yes, 5 feet.
Later the Œleaves¹ or tails appear. These will die off as autumn turns to
winter and the roots sit there waiting for spring. The leaves have a waxy
coat, which makes the plant highly resistant to weedkillers.
Crushing the leaves to break up the coating helps weedkiller to penetrate
and become absorbed but in large areas it is not so easy to crush all the
leaves . However, glyphosate weed killer will have an effect and eventually
kill the plant. You will probably need 5 or more applications. Knock it
back, it re-grows and you repeat.
I don¹t think you can clear this in less than one season.
Amicide seems to be a far more effective weed killer. It can kill it in one
application but may well need two.
I¹d recommend NOT digging where there is horsetail until it is dead for
sure. Otherwise it just starts springing up from the root cuttings. Drying
or drowning the roots prior to composting is a must.
I've been contacted by Mr Charles Bailey who points out that Horestail is
correctly applied to the weed growing on land whereas Marestail is correctly
applied to the weed growing in water.
He also puts forth an organic control method, which he says is effective.
Without resorting to chemicals you can control/irradicate horse tail by
digging/forking through the soil when it is in the right condition: ie not
too wet and sticky!
Once you have removed as much as possible, any that shoots is easily dealt
with. Before it reaches 3 ins/7cm high, hoe off an inch below the surface.
Eventually the food supply in the root is exhausted. Let it get bigger than
stated and food begins to be stored in the roots again, and round and round
you go ad infinitum.
Never touch Horsetail with a mechanical cultivator. If you do you will
understand why it has been around for 60 million years
Glyphosate
This herbicide seems fairly safe. It is systemic, being taken down to the
roots and I understand it is deactivated by contact with the soil. It is not
approved by UK organic standards but I heard some European countries allow
it in organic standards. It is the main constituent in Round Up and
Tumbleweed ready mixed.
Fairly cheap but don¹t use that as an excuse to over use it. The dead weeds
can be composted without the compost becoming toxic. Weed killers should
always be treated with caution"
http://www.allotment.org.uk/articles...What_to_do.php

--
Sacha
http://www.hillhousenursery.co.uk
South Devon
(remove weeds from address)
'We do not inherit the earth from our ancestors, we borrow it from our
children.'