Why Oncidium's Pseudobulbs Shriveling?

[AshKleigh]

Hello! I have been spending the past few days concerned about my new Oncidium. It's an Oncidium Heaven Scent 'Redolence' and is a lovely orchid! I purchased it from a vendor in person about a week ago and repotted it two days after it made it back to my house. Normally I will give the orchid a period to adjust, but I decided to go ahead and repot as the plant was very potbound and a new growth was happily coming in. After peeling carefully through all the sphagnum, I found an extensive root system with lots of healthy roots. Yay! I then put it into a slightly larger pot with fresh sphagnum. However, after a week of it being in my care, this oncidium's pseudobulbs have begun to shrivel. I checked and the roots are still the same, healthy. I'm confused as to why the oncidium is not taking up water and using water from its pseudobulbs instead. Is it normal for an orchid to experience transplant shock when its potted in the same medium? I'm not too worried as it still has its roots.


I wish I had a before picture but unfortunately I didn't take one of the orchid when I first got it. What does everyone think?

[King_of_orchid_growing:)]

Are you certain the roots were healthy and alive?

I just want to make sure it is understood that healthy roots for an Oncidium are white with green tips. When the orchid's roots are wetted, they turn green.

If they are brown or beige that is usually not a good sign.

If the roots in the pot have no green pigmentation to them, it can be more difficult to know whether they are still alive or not. This is where you can do the pull test.

The pull test is when you gently pull on the roots. You don't have to use a lot of force to pull on the roots. If portions of the roots slough off and leave behind a string, those are dead roots. This test is even easier to do if the roots are wet.

I'd also recommend using small grade wood chips for this particular hybrid instead of moss.

[malteseproverb]

How often are you watering? Is the sphagnum dry to the touch? In this weather I water my oncidium types at least twice a week. However, orchids do often experience shock after repotting and it's suggested to kind of let them recover afterward, like keeping them humid and away from too much harsh sunlight. Have you done anything like that?

[AshKleigh]

I looked at the roots again and none of them are coming off when I pull. They are white with green tips on a few of them.

Since I have gotten it, I've watered once but the sphagnum never became completely dry. I more used to watering phals with their wet-dry cycle so my guess is I haven't given it enough water...
That plus the repot are why it's stressed maybe? It is not receiving any kind of intense light as of now (I have it with my phalenopsis orchids). I'm not doing anything special with humidity.

@malteseproverb I will take your advice and give it time to recover, and take more care with watering

Thank you both for your responses and help!

[King_of_orchid_growing:)]

Phalaenopsis level lighting is not enough for this kind of Oncidium. It can take a little bit more light without a problem. It doesn't have to be too bright.

If you're saying that the moss hasn't dried out in days, then water is not the problem. In fact, I'd probably advise you to back off of watering until it has begun to dry out.

If you're saying the roots are fine by looking at them one more time and doing the pull test, then I'd say that they may just be old pseudobulbs going on their way out.