RC: Re: Yellow Star Thistle

[Magnumsmom@aol.com]

Hi Mary,

There are many pages about noxious weeds out there on
internet.  I did a search on google and came up with this
one that lists many good papers on the subject:

http://www.invasivespecies.gov/profiles/yellowstar.shtml

I pulled my horse Magnum out of his pasture home 4 years
ago here in the California bay area because he was eating
the yellow star thistle out there.  I asked my vet about it
and he said that while it takes a lot of yellow star thistle
to cause the palsy-like poisoning, once the horse has ingested
enough, there is no cure.  He said it is very sad... to see a
horse who wants to eat, but can't.  A horse such inflicted
will simply starve to death.  No cure.  I asked if we could test
to see how much toxin Magnum had in his system, and he said
there is no way to tell.  The only management is to remove the
yellow star thistle from the pasture, or remove the horse.

There were other things to eat in the pasture.  This was in May
so there was even green grass.  Magnum was eating yellow star
thistle anyways.  Once a horse aquires a taste for something
they will continue to eat it.

I wrote to UC Davis because I found an article about a bug they
were using to kill it.  I guess the pest works, but you must continue
to introduce it.  Like fly larve management.  I don't know if you can
get the bugs, but you should contact UC Davis about it.  I remember
them telling me I could get the bugs at a certain time of year.

I asked what time of year yellow star thistle dies out, and guess 
what?  It doesn't.  Once it grows in the spring, you have it until
next winter.  Green.  noxious.  I don't know if the dead plants
carry the toxin, but I would assume it does.

Yellow star thistle covers our state now.  It is a non-native plant.
This is one of the reasons there is a push to move to certified weed-
free hay in our state.  If you drive from corner to corner seeing the
infestation of yellow star thistle and fiddleneck, it's enough to grab
the bottle of round-up and start sraying.  After I'd moved Magnum
out of his pasture (which made him really upset so he paced and then
suffered a tendon injury that took us almost a year to clear up), I 
found a bottle of honey in the back of our cubboard.  I'd bought it
at one of those fruit stands out along 120.  It said "yellow star thistle"
honey... as in the bees made all the honey fron yellow star thistle
flowers.  Can you imagine?  I felt really ill to my stomach.  That bottle
of honey went straight into the trash can.

Hope this helps.  There is lots of info on yellow star out on the web.  Me?
I'd get rid of the stuff and try really hard to make sure it didn't come back.
And make sure you aren't bringing more in in your hay.

Kathy Myers
in No. Cal. with Magnum the TB ex-racer
and Mr Maajistic... resident endurance arab