Thanks, Mike. Really what you see is what I was after. I wanted the flowers to be in the foreground, in focus, with a blurred background. Blurred to the point that all it presented was color. I should have used a tripod, but that close to the ground it might have been too tall. Maybe a tabletop tripod?
Is that Woodland Phlox out in the wild? I may have cleared some of the dead leaves out of the background, and focused on the center of the nearest blossom from a little lower angle. Is sun bouncing off of the leaves in the background, but not hitting the flowers? If so, I would have shaded the background. Sometimes that means mounting the camera on a tripod, using a cable release, and shading the background with my body, or sometimes I use an umbrella.
It would be just about impossible to get that entire flower head in focus unless you took multiple frames and stacked them in post processing. so no sense trying to do what cannot be done. That means you have to carefully choose a spot to focus. I would have focused on the nearest flower. The EXIF data doesn't tell me the lens you used, I am thinking a zoom lens. Focal length will affect composition a lot.
I find that background distracting myself and would have shot from a lower angle, or used flash to get more "separation" between the subject and the background and possibly a more pleasing background color. Sometimes I shade the background, as I said above.
You shouldn't need a tripod for that image, necessarily, although it could help. The table top thingees are useless in my experience. I have a tripod that will take the camera right down to the ground, but I hand hold at 1/100th sec. or faster (with 100mm lens, down to 1/30th sec. with a 50mm lens), or when using flash on extreme close-ups or true macros.
How come the motion blur? Was it extremely windy? Were you in an awkward position? 1/640th ought to stop motion.
Good challenge, nice choice of subject, good idea for the image, and close to being a great image.