Love the softness of the background. My personal preference would have been to see the yellow flowers a little sharper, only because it seems like some detail is lost in the bright petals.
I like the soft focus of the shot and the nice control of DOF. My first reaction was the I would have liked a tighter crop but I like the touch of muted color of the blossoms at the top as well.
This is pretty but I think it's lacking some oomph. I might play with levels and curves adjustments. Or maybe contrast. Sometimes yellow flowers are so hard to get right. I've run into that time and time again. I love the softness and the composition but I think the overall tones deserve a bit of work. ;~D