In a message dated 3/21/2006 8:09:47 A.M. Central Standard Time,
<<Can anyone tell me what causes the phenomenon of blooming
out! I separated and replanted one of my rebloomers last year. Two
of the rhizomes bloomed in the fall! Last thing I expected after
separating them and I wondered if that had happened to them. I have not
ever experienced that to my knowledge. If those 2 rhizomes bloomed out
in the fall, will they die this spring? >>
Blooming in the fall is not an indication of "bloom out!" (If that is
the question) Fall bloom after transplanting is not uncommon and should
not be seen as a problem.
"Bloom out" is when a rhizome blooms on all available fans (season doesn't
matter) and does NOT produce increase. Some rhizomes are just teasing and
will put up increase during the next season or after a good soaking rain.
Others simply will not produce more rhizomes no matter what you do. (I've
no idea what causes it, specifically).
You can probably find a lot on the subject in the iris-talk
archives. It's always the favorites that "bloom out!" For me it was
Orange Star & a killer seedling in the early years, and then
Knoble Dragon in 2004/2005!! There have been others but these are the ones