90mm Macro Lens
30 sec, f/22, ISO 125
When you want to make as much of the bloom as sharp as possible, you need to use a small aperture (big f-number) because the lens is so close to the subject. Even then not everything will be in focus, so choose the most important part to be sharp. In this case I concentrated on the center of the flower.
When you set a small opening on the lens, the exposure times may get quite long. So it's a good practice to use a tripod and trip the shutter by using the self-timer set to 2-second delay. These both ensure the camera doesn't move during the exposure and soften the edges.