Jack, Years ago my Celeste surprised me by dropping all it's figs. I was corresponding with Mr. Paul M. Starnes of Newnan, GA (the original "Fignut"), and his answer was that Celeste did that when it was dry.
After hearing that, I tried to water my potted Celeste heavily during dry spells - didn't work. The plant seemed to know the difference between a hose and a rainstorm. I lost another crop to dry, hot weather. It's nice to know that mulching helps. Though for it to be effective on a potted tree, I might have to sink the pot in a pile of mulch.
Thanks for the tip, Celeste is one of my favorites and I really hate losing them.