When you get down to it though, not many plants like wet feet in winter. Those of us with clay soil can attest to that- many such plants are short lived. I was more concerned about things I read about "reseeds proflically" and "will grow out of cracks in sidewalks or stone walls", afraid that it might take over my yard. Many, many plants have tried.
I was impressed by info that it blooms all summer in shade.
Karen