Dendrobium Nobile confusion

[annettehuggett]

This is my first post, I have been lurking in the background for awhile. Thanks in advance for advice. I am a Den newbie. Have had phals for a few years and as seems to be par for the course, the obsession has taken hold, so with 5 types of orchids, my collection is 40+, and I do not have a greenhouse!! So as to my Den confusion .... I succumbed to them at a large supermarket in January! All in beautiful full bloom, typically over wet, etc. After they stopped blooming I transplanted them in appropriate medium. But then I got confused. I live in eastern Canada. Zone 5, so naturally they are grown inside. Most of the orchid advice comes from enviable warmer, Southern Hemisphere conditions. Ok, before I get off track on general orchid questions, my specific Den question is: What do I do now? My research says they need a winter rest. The problem is the time for winter rest was over by the time they finished blooming because they were forced for retail trade (I assume) so .... do I pretend they had a rest and just water and fertilize as is normal for late April in the Northern hemisphere and then stop fertilizing in late August and start the cycle then toward slowing down and winter rest? Thanks for listening
Annette

[ilikeorchids]

Hello and to the forum!

If you had bought the dens in January all in bloom I guess They just bloomed a little early than usual but here in the tropics, that's actually the time they start to open their buds. I think you should resume fertilizing and watering regularly if there are new growths forming or if there are already new growths and they are already starting to grow. You can post pictures if you have 5 posts or more. Happy growing!

[Regelian]

Welcome Aboard, Annette!
Yeah, the nobile Dendrobium types (hybrids of course) are forced for the Winter Holiday market, but this is not far from their normal bloom period. What was done is to rest them earlier. Once the new growth is complete from Summer, the plants are kept cool (10°) and somewhat dry for about 6 weeks to initiate the flower buds. This is their rest. Once they bloom they typically start right into new growth and will need warmth (up to 30°C, but not for weeks) and water. Once they are growing, mine get weekly fertilizer and are only allowed to just get dry. They are in a southern exposue. The canes and leaves should be bright yellow-green, if dark green, then more light. Once the new roots are established they grow gangbusters. After the new growth is complete, they can be placed in a cool spot (yes, around 10°C, like a bedroom window or outside) and given less water. I let mine dry completely between watering during this time, but I do still water lightly. No fertilizer required. I do this in a sheltered spot in my garden where first frosts are in December.

As these plants are hybrids, they do not all react exactly the same and you do need to get used to your plants. That said, I've never killed one, just missed flowers (got keikeis). Some of the most modern hybrids are less reliant on the cooling, but they all need to get dry at the root during their rest. Slight shriveling of the bulbs is normal, as may be leaf-drop (not all do this!). Once you get the hang of them, Dendrobium is, for me, the most fascinating genus you could ask for.

Here is a shot of D. Spring Dream 'Apollon', still blooming after 2 months!

cheers,

Jamie

[estación seca]

What Jamie / Regelian has posted is great advice. Most people kill them by not watering enough, or by keeping them completely soggy wet. They are susceptible to spider mites during dry weather. If you can put your plants outside during a typical eastern Canadian summer, with good humidity, this should not be a problem. Indoors you must watch for spider mites.

Edit June 15 2020:
Yamamoto Dendrobiums in Japan hybridizes and produces a great number of these plants. Their Web site formerly had excellent growing information for hobbyists. Unfortunately it is no longer there. You can still look at the varieties they grow, and maybe see one very similar to yours.

I saved the page, and summarized it in a post in this thread:
Uncertain if Dendrobium is still alive

Yamamoto now has a page showing how to force Dendrobium nobile for Christmas flowering in Japan's climate. There is a lot to learn from that page, but it is intended for growers who can artificially heat and cool their greenhouses during off seasons. Note they use coconut husk for growing medium, which many orchidists would say retains too much water for orchids. For many orchids that is correct, but this is a very thirsty orchid.