Ed,
just so u know, I was worried they wouldn't set fruits in the greenhouse without a pollinator, but apparently they set a good amount of fruits with no bees (maybe the wind, or some smaller bug pollinates them?)
but I've also seen plants that just have trouble setting fruits...not sure why this is...could be cultural, or the plant itself, having trouble with pollen receptivity.
my advice is to keep them wet, but always draining (they can definitely handle a flood). It seems like they enjoy the constant wet/dry cycle, but never totally dry.