I thing you're right fdinaro. I will try to sharpen differently into two different layers so that I can smoothly mix them together for the best effect.
I've also had problems trying to tune the reds, they look oversaturated...
Thanks for the comments
Herve, I tried all summer to shoot these flowers (Lantana). They're extremely difficult to capture. Color is very intense, especially against the greens. Problems you're having are part of the difficulty with these. It might help if you try bringing the gamma (lightness) down a little (but it's still tough). You can also try the "sponge" tool in PS to desaturate, if that's what you want to do. Overall, this is a nice shot.