Oncidium new growths constantly not good
 

So this Oncidium Sweet Sugar that I bought online last spring was not exactly the best purchase I've made.

It had rotten pseudobulbs to start with, one visible and one that I only noticed when I repotted because it was buried underneath the potting mix.

I got rid of the rotten ones, sprayed with hydrogen peroxide 3% and even put some cinnamon powder on the open wounds. Repotted it and hoped it would do better.

It made a new growth and I was super excited. But as soon as the new growth got a little bigger I noticed it was changing color to a yellowish tone, this can't be good I thought and by touching it, yeah it was too soft. The pseudobulb right next to it was also turning yellow and mushy. I repotted again got rid of the bad parts, and did the same procedure again. This time because of the location of the stuff that I cut away I had no choice but to split the plant into 2. So I got 2 separate parts. I wasn't sure that the 1 lonely pseudobulb would make it, since it was just 1. However to my surprise it started making a new growth.

So some time has passed now, and what have I started noticing... the new growth again is changing color and turning yellowish.

There must be something wrong with it, sick maybe? It cannot be over-watering, I am sure. I am keeping a close eye on this plant since I got it.

Anyway, my only hope now is that the other half, no longer attached to this part will make it. It's got a cluster of pseudobulbs and one new growth from this year.

I am also interested in this as I have had similar issues with one of my Onc. And I fear it is just a sick plant that should be tossed

Could it be underwatering? Hopefully someone else will chime in soon.

There's an accordion leaf in there.
How is your humidity? Do have a value?

1. The explanation to the wrinkly pseudobulbs + accordion leaf is that this orchid came like this when I got it. I immediately sensed something wasn't right, and repotted it. This is when I discovered that it didn't have that many roots. So I suspect wrinkly pseudobulbs is a result of not many roots.

On a positive note, the other half of the Oncidium, the one that is still OK, it is making new roots.

2. My house is a bit on the dryer note now as winter has started and the heater is on, around 60%. I am constantly keeping an eye on this plant, like I explained, especially in it's situation. It's in a see-through pot so that I can see if there's still condensation in there...I also do the skewer test to determine when to water. As it turns out I am watering it a little more often now that the heater is on.

3. I just wanted to mention again how hugely disappointed I am that this orchid web shop sold me a sick and in poor condition orchid. As it turns out this is a well-known web shop here in the Netherlands, I even saw a MissOrchidGirl youtube tutorial (I think there's more than one) when she ordered orchids from this particular web shop Orchideeen-shop.nl - Claessen Orchideeen (Claessen Orchids). I did email them with my complaint, however nothing could be done about it as I admit is true I did email them a couple of months after the purchase, and should have done it soon after. My other mistake was not to take pictures of the condition the orchid was in when I received it. Well, I guess lesson learned.

What are the roots like? In my experience, when Oncidium types are happy they tend to root prolifically. Not all substrates and growing situations are suitable for all conditions. I have some that do great in fine bark, one that really likes moss, and a few that were not happy until they were put in a basket and hung. They are all over the map in terms of temperature too.

If it were mine, I’d see if I could dig up some info on the parent species and try to apply it to your growing situation. The plant really seems to be trying, but something just may not be working for it.

Personally, I’d stay away from hydrogen peroxide unless you’re applying it surgically to a lesion or something. Even then, if you suspect rot you’re probably going to be most successful with an antfungal or antibacterial. But, in my experience the die off you’re seeing will resolve on its own if you can make the plant “happy”.

Good luck!

---------- Post added at 11:00 PM ---------- Previous post was at 10:41 PM ----------

I looked up some pictures of yours. I don’t know if this would work for you but I have a couple Oncidium species that look similar as well as a couple of NOID Oncidium hybrids. I have mine hanging in wood vanda baskets lined with shade cloth and filled with small grade orchiata. I have them outside: they’ve all weathered temperatures in the upper 30s Fahrenheit fine.

They seem to like a lot of air circulation in the root zone. They pushed roots through the shade cloth and along the wood slats in short order. My first one, that I tried to grow potted, never put any roots into the substrate and the air roots were short lived, but it turned around quickly once hung and even sent out a big spike.

Hanging, I water them almost daily during the summer opposed to weekly when I had them potted to maintain moisture. I don’t know if a coarse Cattleya type substrate and more frequent watering may have been more to their liking if I’d kept them in pots.

Thank you for your reply. Well, I bought the Oncidium under the name Sweet Sugar. I haven't seen it in bloom yet, so I couldn't say for sure. Anyway, according to this website, it should be a cross between Oncidium Aloha Iwanga and Oncidium Varicosum.

Oncidium Sweet Sugar orchid hybrid care and culture | Travaldo's blog

Well, I can't put mine outdoors at the moment as it's around 32F here right now, and during the day around 41F.

Indoors during the day the heating is in general not on when we're not home, but late afternoon and evening the heating is on. I have noticed that it does affect the humidity in the house, especially lately, it's much drier. I did buy those things that you hang on your radiator and you put water in them, but so far it's not making much of a difference.

Anyway, the other half on the Oncidium is still looking OK, apart from the wrinkly pseudobulbs, but I hope that will improve with new growths. I got one new growth on that side this year, and it's making some new roots I can see.