Stay away from this plant… This is sold almost everywhere, I dont know why… But it is. If you have unlimited space, and no other plants you care about – you can plant it. But it will be there forever!
To try and exterminate it… I try digging as much of it out as I can. What comes back I will then dig out, and if possible spray with round-up, or 24-D. Once the plant growing into another plant it is very difficult to remove. The best way to do this is dig out the plant, wash of all soil, then pull out every little root you can find of the bishops weed.