My experience and observations with the dreaded Seattle horsetail is that if
you got 'em, you will have them. You can continue to clip and dig and it
will probably slow them down but I think it's actually pretty much
impossible to get rid of them. I know that paving crews I worked on would
spray the equivalent of agent orange on a prepared road bed, then pave with
either concrete or blacktop and soon or later the horsetails would push
through. Pretty amazing. If they can survive through that it's hard to think
of anything a home gardener could do to eliminate them short of digging out
your soil and replacing it with sterile material but if there are horsetails
nearby you'll just get them back. I was told that they spread not only by
spores but runners. Sort of draining your property to make it so dry that
the horsetails wouldn't want to be there you just may be stuck. You can
pick lots of the new shoots and put them in a gallon of vinegar and let sit
for a few months, then strain it off and put a few tablespoons in a cup of
water, it makes a fabulous after shampoo rinse for your hair.

Val


"Engquists" wrote in message
m...
Unlike most of you out there, I'm an absolute novice gardener. And
lucky me, my first major challenge is trying to clear horsetails from
a pretty massive yard that I've inherited with my new house.

Initially, I tried clipping them off at ground level every week, but
this didn't stop them from coming back, of course, it just helped
slightly for aesthetic purposes. Secondly, I tried applying Casoron
to a few beds after pulling the horsetails up, which has actually
seemed to be helping and has severely limited their growth for the
past few weeks, at least. Since there are tons of them still left in
the woods, however, I doubt I'll be able to do anything permanently to
prevent them from creeping onto my property. The soil is also
extremely damp (I'm in the Seattle area) so I don't think there's much
I can do to increase drainage.

So I guess my question is whether anybody out there can think of other
solutions or steps I should be taking to at least manage the horsetail
growth in my yard, even if I can't permanently stop the invasion. Are
there other weeds or plants that would crowd them out? Should I keep
clipping them at ground level or just give up that weekly chore? Will
the Casoron likely hold them off for a season or will I start seeing
them reappear later this year?

I know the outlook is bleak with horsetails, but any helpful advice
would be appreciated since I'm way outta my league with this
particular plant...