@Leo in N E Illinois , I think it's just the luck of the draw on the flowering. It was repotted this year into medium sized APL. I put Osmocote fertilizer on it after repotting and added a little pine bark soil conditioner as a top dressing to help with moisture. It grows in the shade of a high canopy oak, so not much direct light, over head watering. I've got a larger one growing near this one that isn't flowering