Anyone? Or is this a first time case? Or is it an effect of the supposed urban heat island? I read that St.Paul/ Minneapolis tend to be a little warmer than the rest of MN, but last winter it wasn't that much warmer. Perhaps the wood chip mulch and concrete structures insulated the seeds a little? I was hoping maybe other people have had a similar experience. I googled the topic and found people reporting impatiens reseeding in zones 7 and up, but not so much for zones 6 and under. I'm guessing by the lack of replies or other topics found here that this must have been a freak case? Maybe I need to purposefully find impatiens seeds and throw them on the ground in autumn to see if it happens again. Also an annual: Petunias - I saw a fair amount of them survive the 2014 winter and sprout up in various places including cracks in sidewalks and in parts of the back patio garden. --- And judging by the color of the flowers and patterns of the I. Wallerina, I can say for sure they had to have come from my garden last year vs. any other display currently planted elsewhere in the city. This post was edited by fieldofflowers on Tue, Aug 26, 14 at 2:16

Floral, could it possibly also be a Physalis species? Is there something diagnostic that makes you think it's S. americanum? Given all the similarity, and variation in the leaves of both genera, maybe waiting to see a flower might be advisable?

Yes to Cyrtonium fortunei

thanks I do not think, Erigeron fits. the leaves a really hairy, almost with bristles there is a lot of Erigeron anuus around, I know that one Hesperis is probably around it is kind of mute now, I know, I just thought that it looked very special or distinct for a weedy volunteer but the Phlox really is a resilient kind, gift from a friend, so I did not want to wait much longer for the NoID to develop and risk the Phlox...