Around here it is invasive and some states it is on the invasive list. I planted some one year and was really sorry the next! It takes it a year or two to get going, but boy did it ever. I had to round up several times to get rid of it. Digging did not work, even a little piece grows back. I understand also that it spreads by seed after little pink flowers.
But maybe in your area it is not like that.