Jon,
Thanks for the information. I have been buying the undiluted Round Up here and it will kill about anything except those Star Thistles. I have tried Weed Be Gone and a dozen other brands and none of them will even turn these thistles brown, let alone kill them. I swear if they put one on a probe and sent it to Mars, within six months they would have 3 acres of them growing well. They grow better with no water and that is why we have none until the Summer comes and the rains stop. Fortunately they are in my upper lot and I don't care about any grass or anything there so I have just tried all kinds of stuff. Except C-4.
Ron
