Thank you for changing the subject, Eric! I know this bad boy and it can be eradicated without a chemical spraying. The one thing not to do if people cannot stay on top of this one is play around with the rhizomes. The best hands on control is do not let this plant head out for any reason. Every time it comes up cut the top at the soil surface, no deeper, with a hula hoe, spade or hoe. I've hand pulled these and later realized if the top is effectively prevented from ever flowering we can get a handle on this one but it will take a concerted effort. I do not know how long this plant has infested that particular area but I would not let Sheep graze this plant for any reason. Jim
I have always been in favour of trying manual eradication of invaders before using herbicides. Sounds like if they are diligent they can take care of the problem in Sebastopol without resorting to chemicals. I certainly hope they are checking the area frequently.