I'm sure this is something simple I am doing wrong, but I have messed with it and can't figure it out so hopefully someone can help me out here.

here is a render I am currently working on. In the wireframe version you can see that there are a bunch of flowers around the sundial, however when I render it only a few of the flowers show in the render. I don't believe the flowers are behind the background. I have looked at it with a number of camera angles and they seem to be in front of the background, but I can't figure out what else would case them to disappear on render :(

Any suggestions would be greatly appreciated.