Last fall / winter I put many of Mexican pings at a west facing window sill that draws the cold from the outside. The leaves became succulent, responding to the cold, dryness, and lower photoperiod. I moved them all back to the rack, which gets southern exposure, along with a fluorescent lighting, as well as moist conditions and warmer temps. I expected flowering. Except for one plant (P. moctezumae x kohres), none have flowered. They're growing nicely and getting some color, but that's it. What went wrong?