Deciduous Dends?
 

I have two Dendrobiums that I don't know how to handle for the winter. One is Dend pierardii and one is Dend superbum, and I read that they are both deciduous. How do they know when it is winter? Are they photoperiodic? These little guys are just seedlings, so I was wondering if I should be giving them a winter rest this year. If so, when do I start? Any advice or information for a newbie with the deciduous types is very welcome. I opted to try with the seedlings first so that if I messed it up, it wasn't an expensive loss.

Thank you!
Lisa
:)

Dend pierardii and dend. superbum are nobile type dendrobiums. In their native areas, the weather becomes dry and the temperature different between day and night are remarkable in autumn, which tell them that they should enter the winter rest phase of their life cycle.
So when they are grown in the greenhouse, start to reduce their water in mid-autumn and they would know that it's time for them to finish growing.

Lisa I grow D. anosmum (superbum) and start withholding all water right after Halloween. I withhold all water and fertilizer (they get crispy dry and drop all the leaves starting from the top) until around late Feb or March when the buds form along the last year's bare canes. Looks like this:

http://www.orchidboard.com/community...uperbum_01.jpg http://www.orchidboard.com/community...uperbum_02.jpg http://www.orchidboard.com/community...anosmum_01.jpg

As soon as flower buds form and grow to approx 1/2" I start water/fertilizer again. By then you should see little green nubbins at base of canes where next year's cane(s) will be. I have two canes on one plant and 3 on other. Hope this helps.

Ross,

Would you go with the same care for a really tiny seedling? Just picked up a Dendrobium anosmum seedling today too at Oak Hill. It can't be more than maybe an inch, inch and half tall.

Solana

Ross said 'nubbins'
:coverlaugh:

Speaking of deciduous dends, I got a senile that seems to be still growing, how can I know when I should stop watering and fertilising?

Hi , If a seedling you want to keep it growing I don't with hold food and water until they are blooming size .
Halloween is the cut off date on my big ones .
Senile , good question a lot of conflicting info. on that one . Gin

Hey, thanks! Lots of great information here! :biggrin:

Do they need high light during dormancy to 'ripen' the growth or is this just a myth. I can't provide high light in the middle of winter lol...

Im with Gin on this one. None of my seedlings (from any genus) pay any attention to seasonality if you keep watering them. I would keep watering it through the winter if you get a new growth. Keep it warm too. Cold weather is the main decider of dormancy. In fact, I believe it was Mauro (Rosim in BR) who does not stop watering his mature plants completely like most people do. Rather (please correct me if Im wrong!) he says his ansosmum spikes just fine with cold weather as the trigger. :goodluck:

Myth. Two winters ago I gave my ansomum dark conditions and this past winter I gave it bright conditions. I got great blooms from both seasons.

I can't speak to Mauro's regimen, but I tried that with mine and I got zero buds. My only regimen is zero water and zero fertilizer during the "sleep" period :biggrin: . Ever since I went with this I have gotten 100% bloom and I'll never change. Just my 2 cents. Remember my last bloom? http://www.orchidboard.com/community...nosmum2595.jpg

I forgot to add that I dry the cr@p out of mine during the winter, like Ross! I dont have the bulbs or the low temps to try and risk a years worth of blooms with a new technique either! :shock:

Winter is the brightest season of a year in most deciduous dendrobiums' inhabitats but not all of them needed intense sunlight. Take Dend. moniliforme for example, it is from subtropical or temperate high lands which usually are cover with deciduous forests but in winter, it is usually cloudy and usually misty in the afternoon. So the sun exposure of the species is not as much as what we might think.
But for some species that grows high in trees or from tropical highlands, high level exposure seems more important for flowering.

But why do they need sun light for if they don't have any leaves left....I have to agree with Steve and Ross on this....sorry I pulled out this topic from last year....lol

Yes, Steve, I don't completely stop watering during the rest period, especially the seedlings. Never had any trouble with my Dends not flowering. Apparently, it is not the dryness or the light that triggers the flowering, but the temperatures. There are several commercial Dendrobium growers here that never stop watering or feeding, but at the right time they take their plants to greenhouses located at the top of mountains where the temperatures are colder. This seems to work good enough to initiate budding. Their plants are always healthy, sturdy, full of flowers and holding all their leaves. A similar thing Phalaenopsis commercial producers use to trigger the flowering process - they keep their plants under a warm, constant temperature, then give a sudden drop that is kept for three or four weeks. This is enough to ignite the flowering process in Phalaenopsis no matter the time of the year - that's why we have Phal flowers the year round. Phals seem to answer very well to the temperature control, but the same control, to the point of making Dendrobium nobile flower when you want, seems not to be possible up to now. But, taking into account the experience mentioned above, it seems that you can keep watering and feeding and then give a sudden drop in the temperature at the right time and have the plants flowering without any trouble.
:) Hey, Blackorchid, it's an interesting question! They don't have any leaves, but they still have green parts and these green parts continue to do the photosynthesis, in a lower level than when they have all the leaves, I agree. When they are resting their metabolic needs are lowered, but don't cease at all and the help comes from the remaining green parts:) .

Thanks to everyone for input to this thread...Mostly to Gin for starting it. :thanx:

I've got a few blooming size deciduous dendrobs that failed to bloom for me this past year, and a few seedling/near blooming size plants. I now have a much better understanding of how to care for them, and feel I've got a much better chance of blooms next spring. :biggrin:

About the particular Den. anosmum, the cane is covered with papery sheath. Does that mean it doesn't need sun light? So far, temperature and dryness are the two critical aspect for next year flowering; sunlight....maybe not neccessary for this species. Am I right...?

So far, experience shows light has no factor in blooming deciduous dendrobiums.

I just acquired 2 nobile hybrids at Orchidfest, and aside from a Den. Super Ise 'Pearl' I bought only 8 months ago, I was curious about with holding water. I'll hopefully find out if my temp drops will suffice or if I'll just get 300 baby nobile hybrids.

Mine came from a vendor in Florida. They said to totally withhold all water. Why not give it a try? What have you got to lose but one season's growth? I keep mine in south window, only because that is its home. No other reason. I don't need keikis, I want flowers.

I finally went and bought a blooming size anosmum from Oak Hill lol....can't help it. I thought it looks much bigger but it looks pretty small and fragile, the stalk is about pencil-thick. I don't know if it's gonna die if I don't water them at all for 3 months lol.... I'm a little scare.

Would the same be suggested for Dend. nobiles? And what about nobiles in s/h? Just continue watering minus the fertilizing?