As I mentioned before, I wasn't at all happy about the shading, or lack of it, for the stems, and needed to do something to improve them. Well, I think I have! Or started to anyway - there's still a lot of stem to do.
Still, I'm happy with the approach. I over-stitched the pale areas in a couple of stems at the top first with one strand of the middle shade, 2211, and then stitched over that with one strand of the darkest, 2213.
Here's the result:
I'm far happier with that, which is a relief. I'll now go on and do the rest the same way.