It's an idea that gets done a lot, but I think you executed it well. The bark has a nice texture and an interesting yellow/green colour. The sky is a nice bright blue, too.
Good to see another "Back to the Future" fan here :) I'm not sure I like the DOF as it's rendered here. I may have preferred to see all of the foreground in focus, then blurred into the background. It seems like it's a rather arbitrary portion of the tree that is in focus.
Nice idea - a whole floral systen - a tree. But could it have all benn in focus? Perhaps loose some of the distracting branches on the left - just focus on the one tree rising "outa here"
i really like this photo, there is a conflict and trickery where the subject is so natural yet the colours and perspective are artifical and un natural. Well done!