I have the same lens, and I've found that shooting at around F8-F11 (maybe a little higher number, even) yields the sharpest results. Especially on such a sunny day, when you're back a ways from your subject, and you want the whole picture to be in focus, you can definitely use a smaller aperture. Hope that helps.
P.S. Using a lens hood would remove the sun's glare from the shot. Sometimes I even just hold my hand up to shade the lens.
Double P.S. There's something wrong with that bench???
Thanks for the input toriaj. I guess I used a smaller aperture number to lighten up the subject but will definitely experiment with a higher aperture next time.