It would be more accurate to indicate where you have found this plant to be invasive. I live in the Pacific NW and do not have any problem with it either reseeding itself or spreading aggressively. It just slowly increases the same as any other perennial. I don't doubt that it is invasive in other regions, just suggesting that knowing where it is problematic would be helpful.

Hi Deb,

I live In UpState NY Northern Catskill Region Zone 5a. My Mom gave me 4 plants 2 summers ago. I planted them under heirloom yellow roses and now they are so dense, tall and growing into the grass. My neighbors keep them in huge containers made from farming equipment. I am moving some to under the lilac bushes for weed suppression.

I had no idea this would happen so I thought it important to add that.

Anita