For Get Pushed this week @mcsiegle challenged me to play around with some settings on my camera I haven't tried yet. I decided to switch my camera to "A" (aperture) and try a few things with a wide aperture. I've had this effect before with my automatic camera using the macro function. For these two images (29th and 30th) I used my kit lens at 55mm and set my f-stop around 5.6.
Wow, you're quick! I'm glad the challenge gave you an excuse to try the aperture priority setting. The branch in the foreground looks sharply focused and stands out well against the soft focus background. Your description of the f-stop you used is lost on me as, although I know what the f-stop means, I still haven't absorbed which setting you'd use for what. Have to study the photography book I checked out from the library.