Oil Painting Process

Here is a painting that I have been working on for a bit. I photographed these Iceland Poppies in Berkeley. Behind them is a chain-link fence so I am trying to come up with a more pleasing background. Some would like the juxtaposition of the chain-link with the poppies, but that is not what I am going for here...maybe later. I am looking for suggestions for how to improve the background. Thoughts I had were to make it the corner of a building, white clapboards, grey patio, more greens, sky...

I turned it into black and white on my computer to see how my values are doing...

Not bad, but not great either. I think I could use more value change in the lower left and right corners as well as in, yep, the dredded background. If I went with a sky background, I could do a darker sky at the top fading to very light toward the flowers and foliage. Or I could do lighter on the right where the light is coming from, then fading darker toward the left. Hmmmm. Please help!