[navcom]

I agree with Tom and Kaze. The time of day is probably a problem. Definitely have lost the top of the tree in the sky. I don't think a polarizer would have done much. The problem is the shadows and a polarizer only helps with reflections but it would have darkened the blue sky a bit. Here the shadows are harsh and short...typical for the middle of the day. Try late or early in the day. Plus this time of day will have a much more pleasing color.

Composition-wise, it's pretty good. I like how the trees on either side "cradle" the main tree. Maybe crop out a bit more of the sky above the tree? This might be a great candidate for a dusk photo with the foreground completely black and the sky ablaze with post-sunset colors.