Depends what type of Dens.
Some Dens(Den nobile & hybrids for an example)do drop thier leaves
just before they need their rest period prior to flowering.
Do you know what Dens they are ?
Welcome to OrchidTalk Orchid Forums
The Friendliest Orchid Community on the Internet!
OrchidTalk - "Bringing People Together to Grow Orchids Better!"
Let us help you grow your Orchids better; Join our community today.
YES! I want to register an account for free right now!
Register or Login now to remove this advertisement.
We had a week of cooling nights a couple weeks ago and after the temps dropped into the high 40s-low50s once or twice I decided it might be time to bring the orchids in for the winter.
All were healthy prior to moving them, but a couple days after bringing them in I noticed the leaves on the Dens had turned yellow en masse.
Did I rush the move? If so, a move back outside should help/hurt/make no difference at this point?
Or did the 45-55F temps do the damage and I just saw the effects after bringing them in?
Depends what type of Dens.
Some Dens(Den nobile & hybrids for an example)do drop thier leaves
just before they need their rest period prior to flowering.
Do you know what Dens they are ?
I bought all three at a clearance sale, all were in poor health and all recovered and were beautiful plants until the recent move. Unfortunately only one--the one least affected, BTW--had a name tag and it reads Thongchai Lai. That one was/is in bloom, currently in the final stages, and only the very lowest of its leaves turned yellow. the other two--without ID labels--have 90-95% of their leaves yellowed, almost overnight following the move. Due to the positioning on the clearance table I had assumed all of the plants were the same, but that IS an assumption.
I find that a lot of these phalaenanthe type Dendrobium hybrids are very temperature change intolerant!
I would say that the low 40's temp did the damage and the plants have decided "too cold" and go into dormancy.
No big deal, they will pop up a new cane when the weather warms up again. Make sure you keep em dryer when it is cold/cooler.
cheers
tim
Thanks for the replies. The temps warmed back up so I moved them back out; now the yellow leaves have fallen off and they do look better without them. The canes still look healthy so the temp-change intolerance must have been at work but apparently without seriously damaging them.
We had a low of 47 last night (days are 65-70) but it will be warmer for the next few days so I'm thinking I'll just leave them out for a bit longer unless someone tells me in no uncertain terms I'm playing Russian Roulette with their health.