Very nice dramatic representation of something we've all seen many times and simply passed. I like the angle at which it was taken and the lighting. Everything is well exposed, although perhaps the reds are a bit too saturated and starting to loose detail because of clipping in that channel. Reds are always tough. In my opinion, the composition as shown is better suited for interior decor but for competition purposes I would crop a bit off the top and bottom in equal amounts, perhaps 1/2 the space off each to make that tulip even more larger than life! Nice job!

After looking at this a second time and seeing Mike's comments, I agree that the flower shadow is too dark. I would also lighten the darker areas just a bit in the lower right parts of the tulip. Leave some blacks for depth but selectively lighten some parts. Also, fix the very bright speckles in the lower right and maybe the others that are sprinkled around the background as well just to remove any distractions.