Thanks for the advice. Went back and managed to take a second shot in the last light of the afternoon - went down to f1.8 this time, but had to increase the ISO to 200. Shutter kept at 1/250. Gave me that reduced depth. Here's the second version....
View attachment 52284
I'd like to see the uncropped shot... I'm undecided, having not seen the shot OOC, but I'm not sure your crop is helping here.
That being said, depth of field is being used much more effectively in this shot and, just as importantly, you've put a little more room at the top of the frame; this additional "breathing room" has a big impact on the shot overall. I think the white flowers are a nice element. Don't be afraid to shoot multiple shots, varying your settings as you go, in order to find the right combination. I would have probably shot this at f/2.8 and f/4.0, *as well* as f/1.8, because at f/1.8 your DOF is going to be razor thin...
.......