I sowed mine last year too. Haven't seen a one yet. But then again, I've only found a few reseeds popping up in the sunniest spots so far. The soil is still very cold. They're not going to sprout as quickly out there in the garden as they would in containers.

I WS'd a lot last season, and they started reseeding
and sprouting last year. I imagine you won't have to
worry about them not coming back. They are also one of
those seeds that come up early and reproduce like crazy.

I like them, but I like them to be under control! :-)