Kenni Judd wrote:
In addition to adequate light, most phals require a drop in night temps to
induce flowering. I've seen various figures bandied about, and I confess I
have not measured, but by "feel" it seems to me that a 12-15F degree diurnal
change is what does it for most of them [plus the night temps have to be
down around 70F or below].

It is my understanding that you can't get a phal to bloom if you keep it
above 68F continuously. In fact, in Taiwan (and other places, no doubt)
they take advantage of that fact to ensure blocks of plants all bloom at
the same time.

Dropping it below 68F for a period of time (I have no idea how long)
induces flowering. I think Dr. Wang at Texas A&M has done a lot of work
here. In Taiwan they have it worked out to a very exact science.

I haven't seen any of the primary literature, this is from a talk that
one of the graduate students here gave last month...

--
Rob's Rules: http://www.msu.edu/~halgren
1) There is always room for one more orchid
2) There is always room for two more orchids
2a) See rule 1
3) When one has insufficient credit to obtain more
orchids, obtain more credit

LittlefrogFarm - Growing the plants Rob likes. )