Cymbidium sinense: Not blooming, maybe needs checkup?
 

Hey friends!

So my Cym. sinense isn't blooming, and I know that they supposedly start to do so around Lunar New Year.

I'm not entirely sure why this might be happening, but my only guesses are:

1. Not cold enough nights?

This plant has been indoors all of the cold seasons, but it as gotten to under 60s (Fahrenheit) where it is in the house a few times (more than 2 times, that is). It's still not fully warmed up here, so maybe nights when it's in the 40 - 50s I can put it out at night?

2. Not enough humidity?

Other orchids (Neos, Dendrobiums) seem to not have issues with growing where they are, which is where the Cym. sinense is, but maybe I do need to try bumping up the humidity. I don't know exactly what the humidity is last I checked, but I believe it's around 50% RH.

3. Not watering enough?

I know Asian Cymbidiums want a drier winter, but I have gone with some decent gaps between waters. Nothing like 2 weeks, but definitely a little over a week a few times. I wonder if sticking to watering every week is better, but I don't think this is the more likely issue.

4. Too much fertilizing during cold seasons?

This is another one I'm unsure off. I know people say to complete cut off fertilizer during cold months, but around when I first got it I gave it some water with a bit of Kelpak and Quantum Total, in order to help establish it in it's new home. I didn't give it the full recommended amount, I halved it.
Again, I don't really know about this out either.


Hopefully it's something obvious, or maybe this is a really "early" Lunar New Year this year and I'll see something closer to spring time.

Kelpak and Quantum Total are not fertilizers, so these shouldn't have any effect as far as blooming is concerned. It's nitrogen you don't want to be giving in winter.

I would not dry them severely... in their habitat, they may not get much rain during the winter, but they have high humidity and moisture from dew. What they do get is more light in winter, again because there is little rain and therefore little cloud cover.

They don't want to be messed with in terms of temperature. You will need to grow them indoors during the heat of summer, but once the weather cools off, put them outside and leave them (let them acclimate) until it really gets too cold. I don't grow Cym sinense, I do know that it is a relatively high-elevation species, I don't know if it can tolerate as much cold as the full-sized ones but you should be fine down to 50 deg F. But again, that is assuming that they have been experiencing the seasonal temperature change gradually. You can't suddenly shock them and expect them to bloom. If they were going to bloom now, they would have started to initiate spikes several months ago. You need to give them the right conditions when they are setting spikes, in the fall, like September/October. What you do now isn't going to change their behavior. Any potting should happen in the spring, again once they're set, leave them alone and don't mess with them.


How long have you had the plants? If this is their first year for you, I think that you just need more patience. It takes a bit of time for them to establish in their new home. Did you get them already potted and established, or bare root? If bare root especially, then they just need another year (or more) If you have had them for two years or more, then you might have reason to be concerned. Otherwise, patience patience patience.

Sinense has a pretty broad distribution range throughout SE Asia, but mostly occurs in the subtropics. I mostly agree with what Roberta has laid out above, with a couple asides:
1. sinense is far less dependent on low temps to initiate spike formation; it can be almost as free blooming as ensifolium; that said, different varieties are known to bloom most frequently at different times of the year--Tao Ge, for example, usually blooms in the spring & summer, whereas Ri Xiang & Bai Mo are both autumn & winter bloomers. I suspect it stems from where over the natural range the variety was initially collected.
2. Aside from light levels [and using a finer media], you can pretty much treat sinense as you would standard Cymbidiums, ie they will readily grow/flower under the same cultural conditions. I grow all of my Jensoa section cymbidiums [ie faberi, goeringii, ensifolium, sinense, tortisepalum, etc.] benched in the cold house with Standards. I can't speak to growing them in the house, as I grow them in the greenhouse, but they are generally forgiving culturally, provided you don't subject them to full sun or try growing them in overly coarse media.

Roberta hit the nail on the head in closing; give your plants a season [or two]; most of the imports that are available are pretty small divisions [ie 3-bulbs or less] and have insubstantial roots. It'll take most at least a season of new growths to bloom, for many another season besides--on the upside, many have interesting foliage to offset the wait [if it's any consolation, I have goeringii benched that I received as single bulb divisions 15+ years ago, which are still plugging away, but have not yet bloomed...patience ;) ]

My suggestion of growing in the house in summer addresses the fact that the OP lives in Texas - where summers can be brutal. In more temperate areas, certainly no need for that sort of pampering. But I suspect that these would be a little happier protected from weeks of hot nights and hotter days.

Andrew from MysteryGardenStore (where I got the plant) recommended that during winter you give it 7-10 days between waters, or whenever the top 2 inches of the the soil is dry. The stick in the pictures is to help me determine the second option of when to water, but I just put that in recently.

The other way is apparently to look at the type of pumice (can't remember the name of it) that turns a mustard-y yellow when wet, and watch for when it goes back to a more off-white for when to water, but I'm not 100% confident about that compared to the previously mentioned ways.

Maybe I've kept them on a drier side more than they actually need.

Makes sense. I'll see if I can acclimate them whenever we get to temps above the 40s again.

I read from Kristen at NewWorldOrchids saying that the Asian Cymbidiums she has can handle temps in the high 30s and up the hundreds if they're in the right light, which reading on that is about 50% shade.
Granted, I don't if she means all species of the Asian Cymbidium group, I can't imagine that includes goeringii, or if she just means ensifolium. I may want to email and double check with her.

Hmm, makes sense the more I think about it. I got it bare root about...3 months ago, I think? I planted it in a mix I also got from MysteryGardenStore. It basically looks the same as when I first got it.

I'm fine with waiting for it to bloom. It a nice looking plant by itself, I just wanted to double check I wasn't getting the culture blatantly wrong.

---------- Post added at 03:24 PM ---------- Previous post was at 03:16 PM ----------

Hmmm, interesting. It's a bit harder to find culture info on these plants, at least in English, so I assumed sinense needed cool temps to start spiking.

What would you consider as "coarse media"? I got a mix from MysteryGardenStore on Etsy that's a mix of some Japanese pumices and medium sized orchid bark.
According to some other places, I've read some Japanese growers grow some of these guys in pure rock/pumice.

Again, maybe this is just another issue of information getting lost in translation.

I think the Japanese "pumice" which is actually a type of clay, is Kanuma (the one that is almost white when dry, orange when wet). There is also Akadama, another type of clay, that is darker. Often theyr'e mixed. Both are used a lot with bonsai. Kanuma is slightly acidic, Akadama is neutral.

I think that sinense does grow more like the "standard" Cyms in terms of temperature. Not as heat-tolerant, but is cold-tolerant. ensifolium grows warmer. I think that for most, you will have to worry more about protecting from summer heat than winter cold in Texas.

That's what they were. Yea, Andrew mentioned you could watch the Kanuma for when to water again.

Hmm okay. It makes me think the sinense and ensifolium would be good candidates for hybridization with other other non-Asian Cymbidiums, but at most I just see with ensifolium. Is this because of where most people who breed Cymbidiums are in warmer areas? Australia being one, I imagine.

Cym ensifolium in hybrids is great for producing Cyms that don't need a winter cool-down and so are a lot easier to grow and bloom in places where people have to bring their plants inside for the winter (so don't get the temperature differential, or good light in fall/winter). That describes a lot of cold climates as well as the warm ones. Those hybrids tend to bloom early (September to November) and so set their spikes during the summer. Some examples are Golden Elf, Chen's Ruby, Milton Carpenter. The last two have Golden Elf in their parentage.

I agree that cultural notes can be hard to come by; something that's been helpful for me is to do a little homework on Tropicos by searching out the species, and clicking over to the distributions tab; once there, you can just plug one of the sites into weatherandclimate.com, and click on the monthly averages tab, which will generate data month by month [ie rainfall, average highs/lows, daylight hours, etc.]; it's not foolproof [ie you'll still have to take into account thermal mass from large geographical features, cooling due to elevation, etc.], but it will at least give you some guidelines within which to work. Simply googling the name of the plant, followed by 'in situ' is also usually quite helpful, as most images will narrow down sites to an even narrower/more precise location [which you can then search out climatic info on...]
There are also a number of us on FB/IG that grow Jensoa section Cymbidiums; the 2 'big' groups on FB have active members throughout Asia, N. America, Oz & Europe--which is great for nailing down/comparing culture & getting help with deciphering sometimes illegibly written characters on plant tags... ;)

What I would consider 'too coarse' is anything over 1/4" dimensionally in your mix. A little bit of media in this range, say 10% or less of total volume is fine, but over that, you run the risk of keeping roots too dry--caveat here: if you're watering daily, year round you could probably grow that way... What comprises your mix largely depends on where you are growing [ie in the house, in the greenhouse, open air], what type pots you are growing in [and what style of pots] & which species in the Jensoa section you are growing. Sinense and ensifolium are both more forgiving of media than goeringii, faberi, kanran and the ilk; for sinense and ensifolium I use equal parts [by volume] of hydrated chopped coir [cocopeat], crushed pumice & medium grade kiryu stone [a type of Japanese pumice that's sort of a calcined clay-pumice hybrid], with a top dressing of about an inch of either pumice or kiryu. For the others, I use a similar mix, though I incorporate large and fine kiryu into them as well; goeringii I have gradually switched over to straight kiryu, about 1:3:2 by volume of large:medium:small, with a top dressing of small grade [if you go the straight kiryu route, you can essentially shift everything to a 3+ year repotting schedule--the media is entirely inorganic]; sinense & ensifolium I repot about every 18 months. Regardless of mix, I grow everything in this section in deep Asian style cymbidium pots [both plastic & fired stoneware].

Hmm, good to know. I think for a lot of plants it's just getting used to the laziness of what other people say to grow plants at for light, temps and such.

I've been hearing about all of the FB groups and I would join in a second if I didn't have my skepticism about FB and if joining wouldn't open myself to the headache of extended family on FB. :lol:

The mix I got from MysteryGardenStore looks to be nothing too large. If I really felt like it at the time, I probably could've sorted the clay and bark into small, medium to large pieces and put them in the plastic cymbidium pot I also got from the same Etsy story from large at the bottom to small up top, as I guess that's the more "proper" way of using the medium, but I didn't feel like sorting clay pebbles and bits of wood by hand at the time. :lol:


While you're here, do you know if breeding between Jenosa species is common or considered a faux pas in Asian orchid scene?

Also is ensifolium just the better species to breed with non-Jenosa Cymbidiums species compared to sinense and goeringii? I kind of like some of the darker flowered sinense varieties (as well as the variegated ones, obviously), but I'm surprised I haven't seen many hybrids that have any sinense or goeringii parentage.