Removal of the plant before it goes to seed, application of pre-emergent herbicides before seeds germinate in the spring, and the use of non-selective herbicides for spot control. There are also much more complex programs if this invasive weed has taken over a very large area.

Hi Shambo, Yes you can control thistles and yes I can direct you to your nears University of CA cooperative extension ofice and get yourself a permit to buy the chemcials to get rid of the weed. We use Transline Herbicide and it's worked so will that all are neighbors have join in on controlling their's. The stuff is a little pricey, but well worth the cost. It's been two years now since we started spraying and we still get a couple now and then, but we just pull them up before they flower. Anyways good luck and get ahold of your local Agriculture Department, they are always too happy to help.
Tamara

Here is a link that might be useful: star thistle control infor