Violetta von Holm Help

[Steve B]

Hello,

I have a quick question regarding this Ondotoglossum. Most research material I can find advise to use fine fir bark as a preferred medium.

Had anybody else used mixed mediums? Right now I am soaking a mix if Small fir bark (medium bark that I cut up), charcoal, perelite.

Am I going to be doing any serious harm by using this as a growing medium? I bought it last September at a local orchid show. It has new growth on it, but the medium that it is in (medium Fir Bark) is taking a long time to dry out. I have had a couple leaves die and one of the pseudobulbs is turning a brown colour. I want to repot it because I am suspecting it might be having some root issues.

This is a Violetta von Holm 'Bianca' (Odm bictoniense x Odm Bic-ross)

Just wondered if anybody had any experience with this orchid, or words of wisdom.

Thanks for the help.
Steve

[Steve B]

Well,

I'm going to take the resounding silence as a "no", and I guess I will have to fly this one alone. For anybody that is interested, I repotted this morning. Here are a couple of shots. The first shot is of the old potting material, the second is of the root condition. To my surprise the roots looked like they were in good condition. I didn't trim any because they all felt firm. Which leaves me even more baffled as to what I am doing wrong. So I did some research and I came across this on the American Orchid Society web site.

Odontoglossums
Odontoglossums and their intergeneric hybrids offer a great splash of color now. Though once thought of as being difficult to grow and requiring cool temperatures due to the emphasis on odontoglossum breeding, the new intergeneric hybrids made using Oncidium and Brassia, for example, are just the opposite. These plants are quite content in more intermediate conditions. New growths generally emerge in the spring, later forming beautiful plump pseudobulbs. Look for the flower spikes to emerge from the inner sheath of the pseudobulb. If your plant's pseudobulbs are shriveled, then the plants have been kept too dry or too wet. Inspect the roots to determine which condition prevailed. If the lead pseudobulb is large, plump and green (and back bulbs are shriveled) but no flower spike is evident, the plants may have been kept too dry.

So the medium I took out was staying wet and not drying out very fast so I thought it might have root problems. But after reading this, could it be that because I had poor drainage that I simply have not been watering enough? Does that make any sense?

Then there is the whole cool temperature thing that factors in. We leave our house open and just accept the temperature of the day. Right now our temp. is 25+humidity. It has been cooler the last couple of weeks with less humidity. Is this too hot for this orchid and the source of my problems? I do have sheared south facing window in my basement which is always a few degrees cooler, but has zero air circulation. Do I move the orchid down there and hope for the best?

Sorry if thi is long winded. It helps my thought process to write things down and then analyze it.

Steve

[Tobi]

Steve,
Although I don't have an Odontoglossum myself, I do know some of my orchid
members that grow them. An eastern or well shaded southern exposure suits
them best. They like to be kept from drying out completely between waterings.
From what I remember they use mixtures of one part coarse sand, one part
shredded peat, one part coarse perlite and four parts fine bark. Also the
night temps should be about 50-55 F. Most of these guys grow in the Andes
where they get continual cool moist conditions.

[Steve B]

Thanks Tobi,

I don't have any sand or peat, but I ended up putting some cut up sphagnum in it to help hold a little more moisture. I guess the one thing I'm still unsure about is the charcoal. Is there a major reason to not use it for this plant? What would that reason be?

I ended up moving the orchid to my cooler basement. I am planning on getting a little fan for it just to get some air moving around during the summer, until I turn on the furnace in the winter. I'll keep my fingers crossed.

Steve

[Tobi]

Sounds good Steve. I would use the charcoal as well. For sure it won't hurt
and it probably will help. Good source of carbon.

[Ellen]

Just saw this post - wish I could have responded earlier to reassure you that you're not mistreating your Odontoglossum. I have this very same orchid, and it seems really tough. I divided it earlier this year and now have three plants growing in exactly the mix you describe - fine bark/perlite/charcoal. It seems to be doing fine, putting out new growths and roots after an extended sulking period, probably brought on by exposure to near-freezing temperatures right after I divided it. It had previously been in a sphag/perlite mix, and was doing fine in that, too. I don't think it matters much what it's in as long as it gets watered enough and has fairly decent drainage. I have mine outdoors, but it was in the GH over the early part of the winter, and in the house when blooming, and it did fine in all those places. Your pic of the roots looks fine. I don't see any obvious problems. The roots of oncidium alliance orchids will sometimes become stained from the medium they're growing in - brownish color is no problem. This type of orchid is a water hog - if it has good drainage, it will take a lot of water. I doubt that your orchid has any serious problem, so just relax and let it do its thing.

[Steve B]

Thanks Ellen,

It's a relief to know that this orchid is more hardy than a lot of the literature makes it out to be. I have been taking it down to my basement overnight just to simulate a cooler night temp. for this time of year. I'm not sure if it's doing anything else than giving me a piece of mind.

And just to add to that, I was giving it a water this morning and I found this.

steve

[Steve B]

Well,

I thought from the picture in the previous post that I had a spike developing. Now I am not so sure. Here is what I have today. This just looks like new growth.

Does anybody have any other suggestions? Is there still a chance a spike will develop out of this? Sorry for the serious newbie question, I bought this orchid last year when it was in bloom, so I am not sure what to expect.
I guess I was under the impression that new growths only start outside of the psuedobulb leaves.



Steve

[kmarch]

Steve your new growth could well develop a spike but not until the growth is mature.

[Orchidflowerchild]

Each leafy bract will be subtended by one or two meristem eyes, from which either a new growth or an inflorescence can develop. The background of this hybrid is a double shot of Odm. bictoniense and one shot of Odm rossii (which are both now Rynchostele, aren't they?).

Here is what Jay has to say about R. rossii
http://www.orchidspecies.com/lemrossii.htm


...aaaaand R. bictoniense
http://www.orchidspecies.com/lembogbictonense.htm

You're looking at a cool growing mountain plant. I used to grow R. rossii and R. cordatum along with the Coccinea-section Masdevallias, which is to say 50-73F and Cattleya light.

Good luck on it. Those Rynchosteles are really fun, when they bloom.

-Cj

[Steve B]

Okay,

Thanks Kevin & CJ.

So what determines whether these cells develop into a growth or an inflorescence? Genetics or it's environment?

So far it has done fairly well this summer, sending out 3 new growths this year alone. I'm pretty sure we will get enough cool temps. for it soon enough.

Just when I think I might be getting something figured out, I get all this new growth from unexpected places (see my other post). It's throwing me off a little and making me second guess everything. I was expecting to see growths develop more like these.

Steve

[Orchidflowerchild]

wdell, meristem gtissue is basically stem-cell tissue. The plant's circadian rhyntms and the conditions thsat affect them generally detemine what the cells start to form, as they grow.

-Cj

[kmarch]

Growths and spikes come form different places on the plant on most orchids I believe it has more to do with plant structures/genetics than with undifferentiated tissue moving in one direction or another given their conditions. For example, with a Cattleya, new growths come form the base and spikes come from the apex, unless some mutation was at work, which would be an exception to the rule and not the norm, you'd never have one of the new growths turn out to be a spike because of the plant's growing cycle or the conditions underwhich it was beign grown.

[Steve B]

Okay,

Clear as mud.

Thank you for all your help and patience.

Steve

[viper]

I think the medium u used is perfect. A mixture is always best. I use mixed mediums for my orchids and they thrive.

good choice!

[kmarch]

Originally Posted by Steve B

Okay, Clear as mud.

Then let me rephrase my answer: it's genetic.

[Steve B]

I took a look at the roots this evening because I had a hunch that things were not going well. If you scroll back in this thread you can look at the roots from 2 months ago. Well, they are all dead. I just cut about 75% of them off. There were 4 or 5 new roots from the new growth that were 10 cm or so. I guess I've been watering to much. It is now under a bag.

Steve

[Steve B]

I guess it's been about year since the last post on this little guy.

I am happy to say that the past year has been very successful. I was able to nurse it back to health. I have had 4 pbulbs and currently 2 new growths since last year.

I have gotten better at my watering, no more pleated leaves. The only thing I am still waiting for is a spike. I am crossing my fingers that this winter brings around something to cheer about.

I just re-potted because it had outgrown it's last home. The roots look great, long, healthy and plenty of them. I just switched to a coir based medium. I have been having great results at keeping pbulbs plump on an oncidium so I decided to try it out on this little guy. It's going to be different going from watering every 2-3 days to 15-20 days. Right now I'm just hoping I don't go back to where I was last year, rootless.

Cheers,
Steve