In my New England garden this plant has self seeded for me since I first sowed it, 5-10 years ago. I'd say it's about 85-90% true with a stray 'regular green' in there here and there. While it does self seed, it's not weedy - I get 6-8 plants that come up/back each year. Some years a few more, and I either pull them or dig them and give them away. I don't find it invasive. I also don't know if it's short lived as some comments in this thread have made me wonder, but I find it a reliable if restrained reseeder. I have it growing nearly full sun, and relatively thin soil (my gardening friends tell me NONE of my soil is "thin" but it seems happy in the sunnier, thinner soil areas).
I like it for the pop of yellow it offers and it's undemanding nature.
