I have them and they are the sweeeeeeeeetest little flowers
I love them..
They come up early spring
They do eventually spread/naturalize...
but they are verrrry far from aggressive..
*very dainty actually*
They do only bloom for a short period,
and they do disappear in the early summer,
*so, to me that's the only bad part, as I don't dare plant
anyyyyyyything where they are, cause they are very easily disturbed or not to come up
if you let something agressive go over it..
*I know that from experience cause I let some creeping phlox by it, thought it would still come up thru it, but it engulfed it*