Oncidium yellowed leaves
 

Hi there. I’m getting the feeling that my oncidium could use a little help. It’s a rescue that I’ve had for nearly 3 months now. I got it with one air root only, all desiccated roots in the pot.

Now it’s got a bunch of nice roots growing through the pot and some new growth. However the leaves are getting yellow. Is it getting too much light? I’m trying to base it’s health off the new pseudobulb.

I water it pretty frequently, about every day to every other day since it dries out pretty fast. The hunidifier runs on it 24/7.

Are ALL leaves going yellow? If not, and it the new growth is nice, then most likely ok.

In relatively bright light - some lighter shades of green is expected, and often preferred - which is linked to getting enough light for lifting chances of flowering in the future.

Also - aside from occasional fertilising ------ and if not applied already ----- some occasional mag-cal application can be helpful too.

Also - for relatively old leaves ----- eventually they are going to yellow and even drop off etc.

It looks normal.

New sympodial orchid growths consist of stems with multiple nodes. The first part of the stem typically grows horizontally and we call it a rhizome. The next part typically grows upright and gets fat; we call it a pseudobulb. All along the stem - rhizome and pseudobulb - there are nodes, normally with a leaf or bract. A bract is a small thing like a small leaf that grows off the stem. Inside the base of each leaf or bract is another glob of tissue that can divide, called a meristem. The meristem can become another growth, or it can become a flower spike.

It's easy to see on Cattleyas where the nodes are on the rhizomes. The bracts drop off and leave circular whitish scars. As Cattleyas mature the new growth is enclosed in "sheaths" that turn brown when finished; a lot of people peel these off the pseudobulbs. These are properly called bracts.

In Oncidicums the bracts around the developing pseudobulbs often are something between a flat bract and sticking out like a leaf. That is what is getting yellowish on your plant. In many of them this bract/leaf turns brown and dries after the new growth matures. This is happening with your plant. The leaves will continue to grow until they reach full expansion. There is a chance a flower spike will come from inside one of the developing leaves. Inside the bracts the meristems often produce new growths, and the cycle continues.

The new leaves look great. Any yellowing on the old ones is force of nature... the plant looks like it is reviving nicely.

As always, thank you guys!