Frillylily, I started mine from seed last spring and they've all come back bigger and better this year.
I have no idea if they spread by seed and/or making new plants, but they (meaning each individual plant) have gotten so big this year that I'm going to have to transplant quite a few of them to give them more room.
They were so easy to start from seed that I'm going to assume that they are at least capable of being spread by seed.
So far each plant is producing only one color.
