Thanks for posting this Roger. It takes a lot of courage to post something in public and I think you've done a great job with this one.
Some general ideas without any order:
1. I like how you've flouted the "rule" (guideline, really) that the background should be darker than the subject. It makes for an interesting contrast. I also like the unusual arrangement and choice of slightly withered rose. Again, this is a more interesting composition that the run-of-the-mill bouquets. The depth of field really works here - the rose is in focus, the leaves not. Perfect.
2. I have a few problems with it too: there are too many dark areas, specifically in the lower centre and left of centre - we're missing details. If you have Photoshop, I suggest using a curves adjustment layer and trying to recover some of the detail in the dark areas. I would also clone out the distraction of a leaf(?) running parallel to the stem.
3. Things I would do (not necessarily 'improvements', just different ways of approaching it: apart from lightening the dark areas, I think there is a bit of noise, which can be removed. At the same time, I would sharpen the image quite dramatically - but be wary of introducing 'noise' artefacts in so doing. Again, in Photoshop, there is a sharpening technique entailing a copy of the background layer with the blend mode @ overlay and a filter @ high pass = 10 pixels. That should work.
Below is an attempt to show what I meant. It's not intended in any way as an improvement, just as an example of what could be done. As I was working off the lossy jpg above, I've actually introduced problems which don't exist in your version (noise, clipping, etc.). Tell me what you think. I was interested in the skinlike texture of the rose, but I've made the dark areas darker in the process.