How have you been fertilizing them? They are kind of picky eaters and if you give them too much nitrogen by itself, they won't ever fruit (same with peppers too). If you haven't fertilized them at all, then you're depending on your soil to give them the nutrients they need and it's usually lacking in at least one area.

If you give them a little Phosphorous heavy fertilizer, they should start fruiting. I usually give less than the recommended amount, but more frequently.

Great! I had forgotten that phos could be the problem. I was using an all-purpose organic fertilizer, but I can put some bone meal in the soil around them.
Will bone meal be too slow release?

I typically give fruiting annuals a chemical blooming phosphorus fertilizer. According to this article I'm linking, bone meal won't provide phosphorus to plants unless the soil's ph is below 7.0 (which is rare in AZ). Also according to that article it takes at least 1 month to release the phosphorus.

Here is a link that might be useful: Organic Fertilizers

This post was edited by iAndy on Sun, Jun 8, 14 at 18:26