I have Koopowitz's slipper book, when I get home I'll see what he says.
In regards to my calanthe, this past fall it put it, along with my Bletilla, in the root cellar at work...1-4 C all winter. I brought it into the warmth only 2 weeks ago. It tried to bloom 2 years ago but blasted. I hope it works this year. I have two others that I treated the same way but neither of them will be blooming this year.
