No idea what it is, but it looks very nice.
An idea though might be to pick a bloom or take your picture, go find an older man or woman who's working in thier garden, and ask them if they know. It might be a native of some sort.. Or you could try asking a local nursery..
I say this because I had a similar question about a beautiful tree blooming back in the early spring, and no one could tell me what kind of tree it was, but when I asked my girlfriend mother (in her late 70's) she knew right away the tree name and what I was talking about. Sorry I can't pinpoint the plant but maybe you can find help nearby.
my discovery was the eastern red bud tree. Probably common knowledge to some but it wasn't to me.. Anyways good luck!