Get rid of St John's Wort?

[Vanisle_BC]

I have a huge, ever-expanding bed of St John's Wort; wish I have never planted it. Each year it encroaches further into the rest of the garden. I wonder whether I could get rid of it by repeatedly mowing it to ground level: Opinions?

[applestar]

I wish you could dig some up and send to me. St John’s Wort is on my wishlist for my topical use herb garden.