IMHO, the small tree doesnt do much for the pic but it doesnt detract from it, either. I think the shade is about right. The trees on the right are just perfect. I love putting old fence posts in images, I would certainly leave this in. A few more differntly coloured flowers would look good. I think this pic is going to look its best without being too fussy so I wouldnt look to add many more elements. It has a great composition.