What Chris says is right but subject distance and size also come into play. This was taken at F11 but it was only about 150mm away. The stem is already way off focus and it's only about 100mm away. If the stem had been 1m away it would have been that far out of focus it would have been unrecognisable.
The lens was set at 42mm.
All older guys have a moan but depth of field was much easier to tell when every lens barrel had the DOF scale around the outside
