Dendrobium dropping leaves - can you regulate it?
 

Two of my dendrobiums, Oriental Smile Fantasy and Rainbow Dance are currently undergoing winter treatment with night temperatures going down to 45-50F. Both are shedding their leaves and soon I'll have leafless canes only. From what I've read it's quite normal but at the same time I've seen lots of photos of both flowering WITH nice green leaves- which would be my preferred option. Are they dropping the leaves because of the cold treatment? Is it true that higher temps (so cool not cold) also stimulate flowers but at the same time the leaves are retained?

---------- Post added at 11:08 AM ---------- Previous post was at 10:51 AM ----------

And also- do these (and D.nobile and nobile type hybrids) need a day/night temperature difference during winter rest or is constant low temp OK? Right now I'm constantly moving them out and in :)

I don't know. How cold is it at night outside? If it doesn't freeze you could probably leave them outside.

Hi,
if I'm to speak from experience, then your nobile types should keep more foliage if you don't make the winter rest as severe as many sources advertise (water maybe once every 2 weeks in winter), but they really need about one month of significant day/night temperature drop to induce flowering. They should be OK outside as low as 4 Celsius, but not for extended periods of time. Here, in Canada I put my nobiles out end of May and bring them back inside when night temperatures fall below 10C- that can be even November sometimes. With this treatment I get flowers twice a year: sometime early winter and second time late spring. I hope this helps, enjoy the bloom ;).

Thank you! Night temperatures right now do not drop below 6 Celsius, so I've left them permanently outside for now. I guess a bit higher temps would be better but it's either that or 20+ Celsius at home.
I do hope I get some flowers otherwise I'll only have flowerless and leafless canes :)

If they are large enough to flower and didn't get fertilizer too late in the summer, they should flower for you.

Thank you, that's very helpful. But what period would count as extended?

---------- Post added at 11:10 PM ---------- Previous post was at 11:06 PM ----------

The problem is, I got them only a month ago, so I don't know what fert regime they had. I bought them as flowering size plants though to my newbie eyes they are quite small ;)
I guess I have to wait and see :)