I'd say in learning DOF you nailed it. Distracting background, and you put it completely out of focus and drawing all the emphasis to that dead phucking plant
I'll give it an A in the technical aspect of proper use of DOF.........other than that , I'll take the 5th
All BS aside, this is one of the assignments in most beginning photo class. "Show long & short DOF"
........so now let's see the opposite use.....
Oh and your ISO of 100 was just fine. I'd say 400th was plenty fast enough to catch a dead plant.
400 ISO would have put you at 1600th of a second.....no need for it, and you would have got a tad bit more noise in your shadow detail. Your exposure was dead on. You could add about 15 fill light in lightroom, or a tad of Shadow / Highlight in photoshop to bring the shadow detail up. But your histogram from that shot is dead nut.
....oh and your color is more true to life, BD's is way to heavy on magenta.