Well, that's interesting, because I've read in a couple of places that it does self sow....perhaps not as much as they say however. This last winter was particularly bad for the prolonged deep freeze that we had here in New England, and I imagine you may have had it even worse. That may account for it's failure to thrive this spring.
Well I hope you get some seedlings from your sprinkling in case your mother plant doesn't make it.
Thanks for replying!