Well -- I did a fast check and don't seem to be having any problems with Tom Johnson Irises that I grow here. Thankfully. I wonder what the difference would be between your place and mine?
To answer your question, Jan -- Tom Johnson is my favorite hybridizer. This is not to take away from Blyth/Ghio/Keppel Irises -- they're gorgeous and these are wonderfully talented men. But there's something about Johnson Irises that grab my attention and admiration -- even before I know that they're his. He just creates flowers of such beauty.
