Emergency oncidium repotting

[Cattleya234]

Hello, I hope anyone reading this had a good Halloween. I just bought my second oncidium, and saw some problems. The moss it was potted in was suuuper degraded and compacted, and had algae, bacteria, and fungus growing all throughout it. Normally I would’ve just repotted and not thought about it again, but this orchid is in full bloom. Will it drop its flowers? Is there any way I can keep it blooming? I’m potting it back up in some fresh moss, and it’s already acclimated to the light that I’m giving it, so will it be ok? It still has a fair amount of healthy roots left, and none of the pseudobulbs are rotten, so will I be able to keep it in bloom? I tried my best not to disturb the healthy roots, and cut off any dead roots that I saw. I’m also going to let it sit out for a day to let it dry a bit. And I promise, this isn’t the same oncidium as the other thread I made about mold on the roots. The store I got them from just generally tends to overwater.

[Roberta]

My inclination would be to just cut back on the watering until it stops blooming and starts new growth. Base your watering frequency on the condition in the pot (aim for "just damp" before watering again) rather than trying to do it by the calendar. Reducing the moisture level will keep the algae, etc. under modest control until you repot.

[Cattleya234]

Thank you!

[estación seca]

Oncidiums usually drop any flowers if repotted.

[Cattleya234]

Ok, so I ended up checking the roots again today and found a huge, slimy clump of pure algae. That was it. I couldn’t handle it anymore, so I repotted the orchid then and there. It’s in clean moss now, and I think it’ll do better. However, while I was potting, something fell off the plant. When I looked closer, it was what I had thought was the new pseudobulb growing. But this doesn’t look like just a new pseudobulb. It has its own roots, and new growth of its own. Is this a basal keiki? It looks just like a tiny version of the main plant. I can’t find much info on how oncidiums produce keikis, but this definitely looks like what I would expect one to look like. Thank you again for all of the advice you’ve given me!

[Roberta]

Definitely looks like a keiki - if the roots were really bad, might have been a "defense mechanism" to grow a new plant. Now you have backup... A lot of people on the Board have excellent results with the semi-hydroponic approach. Might be worth a try.

[Cattleya234]

Yay! I’m glad I have a backup now if the main plant doesn’t work out. I’ve always wanted to try semi hydro, but I’ve never had a good reason to. Now I do!

[debrabarne]

Oncidium is transplanted only as needed (when the substrate has become unusable, the roots have completely filled the container). Choose a wide container for the plant. Use a special composition for orchids as a substrate or prepare it yourself. It should contain river sand, pieces of bark and charcoal, sphagnum moss, peat.

[SouthPark]

Originally Posted by Cattleya234

I couldn’t handle it anymore, so I repotted the orchid then and there.

That was a good and sensible choice.