Winter rest requirements for Dendrobium harveyanum?

[Roberta]

I haven't jumped in on this one because my growing conditions are really different than for people who grow indoors. I have a bunch of deciduous Dens from the similar Himalaya, China SW and SC area but not this particular one. (I think I need it... I love frilly orchids!) I generally don't dry them out particularly, but they do get a lot colder than they would indoors. And bloom. (It is also likely that "wet" where I live, watering for a minute or two every few days with only occasional rain, is closer to "dry" in habitat where there is humidity and dew.) So, I wonder... maybe there is more than one "right answer"! They may not need "cold and dry", maybe "cold or dry" does the job. Since none of us lives in the habitat, everything we do is a compromise, and sometimes we hit on something that works!

[camille1585]

Great news, I'm pleased to report that my Den harveyanum is starting 3 spikes right now!

I stopped watering and fertilizing around the time of my original post (late october), and throughout the winter I lightly misted the top of the substrate 1-3 times a week. I was planning on starting watering again around Valentine's day, but started today on account of the spikes growing.

[camille1585]

Thank you all for the excellent advice last year. The flower count is a big improvement over last year's blooming!

Next resting season I will try to keep it a bit cooler to see if that further improves the flower count.

[Bamanana]

Camille, your orchids are stunning! You are quite the photographer! I enjoyed browsing through your photos.

[Roberta]

An observation from my Dens this year... I didn't dry anything out, was not able to move my plants around due to surgery that cramped my style for a couple of months. (Starting to get back to work on the orchids) Den nobile types in particular... they didn't get dried, but they did get chilled (complements of Mother Nature). And blooming better than they have for a long time. Lots of other deciduous and semi-deciduous Dens (mostly mounted or in baskets) I never move away from water following the "Andy" approach, and they're budding too. So I suspect that "rest" has both a "dry or drier" component and a "colder" component. and for at least some, one or the other alone may be sufficient. Some species likely are fussier than others as far as needing both, but it may be a continuum.

[camille1585]

Thanks for the insights Roberta!

For my Den it will be difficult to know if cool+dry is necessary, or if dry is an acceptable (though suboptimal) substitute to cool. I live in a very well insulated apartment in a climate not at all compatible with keeping an orchid outside all winter.

[Roberta]

Another thought about a factor for triggering Himalayan Dens... increasing light. In nature, when the rain goes away, so does cloud cover, so they are exposed to much more light. When growing under lights, that is something that could be tested that isn't possible to control when growing al fresco.

[Dusty Ol' Man]

Putting this here because it fits. After reading this today, I went out to check and maybe add a spritz of water. Lo and behold, there is action! Thanks to all the contributors to this thread. You keep me sane through the waiting.

[FranningtonBear]

Originally Posted by Fairorchids

Some Dendrobiums do
The one detail, which most writers neglect:
For all the winter rest Dendrobiums, it is critical that you stop fertilizing. The general rule should be:
mid September: No more fertilizer
mid October: Reduced watering
.

I’m so pleased I found this board, a quick search and I have found some care advice that is directly applicable and easy to understand. Love it ❤️