Thanks for your very well detailed summary! All this helps put the pieces of the puzzle together. I've had it too--in exactly the same way you explained it, but mine were Orientals (three plants) Up 'till now Orientals were involved. Now recently, other types are being reported. There is communication back and forth outside this forum taking place and a couple of us here are exchanging information with certain North American growers. Right now, it seems the hot March, frosty late April-early May plus the hot dry June (with high emphasis on the late frosty period) as major contibuting factors. It didn't necessarily have to show frost damage to the tiny delicate inner leaves of the rosette. More information may develop shortly.