"Engquists" wrote in message
m...
Pulling them, rather chan clipping, will get more of the root, and slow
them
down more. I've had some luck spot spraying with weed-b-gon or roundup.
Spray the new growth, then let them be. Spray again if they don't die
back.
Use a sharp flat bladed spade to slice 12-14 inches deep all around your
yard, to cut off the nutrient supply coming in from roots outside your
yard.
That, and constant pulling, will get them eventually. Don't let them get
tall, that just lets them build up the roots. It is not a one year
project.
It might take several to clean it up, but you will see gradual
improvement
if you keep after them.

Bob

Thanks for the tips, Bob. It's nice to hear somebody with at least a
little optimism that I can get the horsetail under control; I'll cling
to the illusion of hope, even if I lose the battle in the long run.

I did find it interesting that your advice about pulling the roots
contradicts what I've read in some other messages. Many people have
said that pulling the plant up by the roots stimulates it to grow even
faster -- for some scientific reason that eludes me -- and have
suggested clipping that plants at ground level is a better idea since
it will theoretically help starve them via denial of photosynthesis.
I'm assuming you disagree with this and suggest that I just go
straight for the roots?

My theory is that the plant will have to use up more energy growing a new
root to the surface, but I could be wrong. IT did seem to work for me. Try
Weed-b-gon on them. It seems to have worked better for me than roundup. Just
spot spray the stem as soon as you see it, and maybe a couple weeks later if
it still seems lively. Again, cutting the roots from outside your yard will
help immensely, although it will keep the poison from reaching them. You
could even put a sheet of something hard around your yard, underground, as a
fence blocking the roots from re-entering. I've used sheet aluminum for
this. Just make sure it goes below where the roots grow to ground level,
probably 12-14".

Bob