Hi Steve: i like the simplicity of this photo. would suggest cropping off most of the right hand side in order to put the flower on the upper 1/3 cross hair. i see that you mentioned darkening the background, personally i don’t think i would go quite so dark.
I like colors. Darkening looks good for me. I’d remove small white spot in the top right corner (visible on Flickr). The left part with bud seems too competitive to the right one. I’d darken it a little bit. The leaf on the left is cut. It looks weird. Can you include whole leaf?