Your glow looks "pillow shaded". This is because you have used a gradient in the outline. I guess you could obtain a better result by using an Anti Aliasing technique and a color that would have more contrast with the flower, in order to focus the image on it, instead of the external glow.
I hope this helps:
Hi, Thanks for the advise, I will check it. This is my first time on this website. I guess I need to move this to WIP forum before uploading here :) . Thanks