I have a wooden mailbox that sits beside my driveway approach. About 4 feet from and 3 feet behind the mailbox is a locust tree that provides morning shade, but not afternoon. Under that tree I have a circle of ajuga and ground cover phlox. What I'd like to do is create a bed that connects the circle and eliminates this awkward mowing area between the tree and the driveway.

I was thinking about a clematis and some daylilies, but wanted to plan something with extended bloom.

Any ideas?

Thanks.