Dying dendrobium - yellowing canes

[jenzed]

Hello orchid medics. I have a Dendrobium Oriental Smile (Orchid of the Week Library: Dendrobium Oriental Smile 'Fantasy' AD/AOS) which I won in a raffle at an orchid show in the spring (which is kinda neat because I'm kinda an orchid newbie).

One cane was dying / dead when I got it (or declined so quickly that it just seemed like it was already dead). Now a second cane has died. The dead canes are yellowy brown and hardish (not especially mushy). The leaves and root clusters on the oldest of the dead cane seems to be doing fine, though.

I moved a couple of months ago, and it is now in a moderately high light spot that is quite cool. It seems like the second cane died quite quickly over the last week - I only noticed it today. I let the plant dry thoroughly between watering. I can't see any bugs. I haven't taken a look at the root ball.

What should I do? Do you think I can save the plant? If the canes are doomed, is there some way I can save the growths off the canes (the root / leaf clusters)?

Thanks for your advice - it's a lovely plant, and I'm sad to be losing it.

[karren]

This is a nobile dendrobium and it responds to season changes by blooming after experiencing a month of cold nights. Mine live outdoors, in full sun, from the first frost free night(early May) to the last one(late Nov.) and get the seasonal change that way. Mine are currently dropping leaves and budding up-- one is even in bloom.

Yours looks like it has not had this kind of care and has grown a bunch of kiekis (baby plants). The good news is that these are robust orchids. I would remove all the kiekis-- the ones with enough roots can be potted up separately-- and the dried canes if you want. This will direct the plant's energy to growing new canes-- from the base. I don't think it has any growth that can bloom this year so I would just put in bright light, water and fertilize it regularly and hope it will grow a new cane. If a new cane grows and it has a seasonal cool down next year it may bloom next winter. These plants do not like much messing with their roots and like to be in small pots-- when the pots are full, full of roots it is hard to over water them. On the other hand they tend to grow tall 30" for example in a 4" pot and tend to fall over a lot. Each fall in breaks something off at my house. Hanging the pots keeps them from falling over and cuts back on the damage. Hanging them has been the aha moment for me.

[John D.]

I agree with Karren, remove the kiekis, water well to make the roots pliable, unpot and check the roots, remove any bad ones and the dead (yellow-brown) canes If they are green even with no leaves they are alive and probably repot in fresh medium. I'd put the kiekis in with the parent unless you want mulitple pots of the same clone. As they grow they will give you a better show quicker and can be seperated later if you desire. You may need to stake the plant until it settles in and grows some more roots.

[Sandy4453]

Shouldn't these Nobiles get a completely dry, winter rest? I stop watering from Nov. through mid Feb., when buds start. I've heard these do well in s/h but that aside, shouldn't watering be withheld?

[karren]

I don't think that keeping them dry is the critical factor to getting these to bloom. I think that they need to be subjected to a month of cold nights.

My experience showed me that they bloomed much better when left outside into Nov. here in Ohio. But which of the seasonal changes--temps, light ,rain-- was the trigger was not obvious to me. Then I found this on the site of a commercial grower/hybridizer in HI. He has no fall like we have here so he had to figure it out. It takes 25 cold nights to trigger the bloom cycle. As the temperatures drops one waters less, and here are his hints on watering.

Watering - There is a direct relationship between temperature, light, and watering. When temperatures begin to rise in the spring, gradually start watering. In the summer, when temperature is high and sunlight is strong, water almost every day to keep the plant from drying out. From about late September, when temperatures begin to fall, gradually reduce watering. When night temperature falls below 50 F (10 C), water only enough to keep the canes from shriveling. Once a week should be enough. When night temperatures fall below 41 F (5 C), keep the plants dry. If you have a greenhouse in which night temperatures in winter can be kept above 59 F (15 C), water lightly whenever the plants are dry. It is important that the amount of water applied in the morning to the media be dry by evening time.

Let your plants speak to you. If the canes start to shrivel they need water. Most of mine are in the greenhouse and budded up now, one is even blooming. I water all of them weekly and the shrivelled ones a little more often.

[jenzed]

Wow - thank you all so much for the advice. I am very happy that I will probably be able to save the plant. yay!