oncidium question about yellow leaves
 

Couple of older leaves on my Oncidium Sharry Baby turned yellow. The pseudobulbs are firm, roots look healthy, new growth is progressing.
Are those yellow leaves just normal aging process or signs of something wrong?
This is my first onc., so I have no experience with them. Sorry if it is a dumb question.
Thanks a lot.

I would say it is just natural progression on an older pseudo bulb. The side leaves go before the centre ones which could hang on for a long time after. They appear to be just yellowing and no signs of rot or anything at all. Since the roots are good I wouldn't worry. Some shed their leaves faster than other ones.

Thank you Silken. That's exactly what I wanted to hear :).

First of all it's definately not a dumb question. Occasionally older leaves on oncidiums will turn yellow and fall off. On the other hand the leaves on yours do not look all that old. Oncidiums need a little more moisture than some of the other orchids with psuedobulbs. They also prefer good humidity and air movement. I would water a little more often and see if that helps. The next time you pot an oncidium you may want to use I finer mix that will retain a little more moisture because oncidiums have fine roots. They do need good drainage and they need to dry out between waterings. I moved mine from hydroton into a mix that is mostly coconut husk chips in a platic pot with good drainage. They seem to do better that way. Of course everyone grows differently so try to find what works for you. Good luck.

I too thought the bark was quite a bit chunkier than what I pot mine in. But since the roots were fine and PB's quite plump, I figured it must be OK with your conditions. I agree, I would use something finer next time.

Humidity does go down now because of the heating.
I am watering twice a week.
I have some chc at home, can I re-pot it now?
I have a small psychopsis plant in bark too. Since it is a relative to oncidiums, would it be better in chc also?
Thanks a lot for your help.

Watering twice a week sounds fine to me. If the roots look good you could wait until spring to repot. Orchids don''t grow much this time of year anyway.

Thank you Tucker85.
Well, to really make sure the roots are ok, I took it out of the pot:
http://2.bp.blogspot.com/-tZx_w1CoAR.../onc_roots.jpg

They seem fine and have some new growth. I took out large pieces of bark from mix and added some chc instead. Now the mix should retain more moisture, but I probably need to water it less frequently, maybe once a week.
Does it make sense?
Thanks again.

1.) There is no such thing as a dumb question; you will never learn unless you ask.

2.) The yellowing of the leaves is a perfectly normal thing, which is semi-predictable; usually the side leaves go first, and the top leaves stay a year or more longer, but sometimes the plant doesn't follow those rules.

3.) The Sharry Baby generally prefers more water, because as you seen, the roots are fine. Your plant didn't show any real signs of under-watering, which is a good sign. The best way to see if you are under-watering is to see if any new leaf growth pleats.

4.) Yes, with a more water retentive mix, you will need to water less. I think you should wait until the mix is almost completely dry to water again, which I cannot say how many days since I do not know your growing conditions, and the time will vary on the season.

5.) You have a very healthy looking plant on your hands, so you must be doing it right! Good job! :D

Thank you.
I thought that leaves should age and drop one by one, so the fact that I had two leaves yellowing at once scared me.
I agree that watering schedule depends on one's conditions. I also hope that adding chc will help with humidity drop that we experience now with heater working.