Debbie, regarding your 3 hives on the Lavender farm .

You stated only one had honey and you did not know why the other two are light. I assume all 3 hives had the same environment, were they near each other or at corners of the property or shaded or some such. 

Assuming the same hives, same exposure, and same food sources available. My first thoughts, since the 3 colonies shared the same geography, were genetics. Like maybe one colony was a wild capture and the other two were "farmed" bees?

Which immediately leads me to think about giving the nod to the genetics of the hive that was productive, and maybe re-queening the 2 that weren't. Or at least, the productive hive would be my first candidate for splits. 

I am interested to discover the cause as I think there is some potential for learning. That seems irregular or at least distinctive that one hive would prosper. 

Also I could not find where to sign up for field day and would like to participate if an opening is available.