Oncidium Twinkle still yellowing...

[greenpassion]

I had posted earlier in the month about my newly aquired Twinkle with yellowing leaves. The pb is also yellow. It is still in bloom, tons of blooms, but the leaves and one of the pbs is very yellow. I got a heat mat (just came yesterday) as someone said oncidiums need warmth at the roots. It's in the same plastic pot that it arrived in, with narrow slits in the sides, in a bark mix. I keep the temps around 62, and the humidity around 55%and now, as I said, it's on a heat mat as well. What should I do to stop this yellowing?? Do they yellow from too much water, or not enough? roll:

[Otis226]

Unfortunately, it can happen from either too much OR too little water. Are you familiar with the technique of using a bamboo or wooden skewer inserted into the potting medium to check the moisture content in the center of the pot? I find it somewhat helpful with some of my more 'mysterious' 'chids'! Leave the skewer in the medium for several hrs. then You remove the skewer and check how damp the tip is. You only water when its approaching dryness. Good luck, I love the Twinkles.
Best,
Tony

[greenpassion]

Thanks Tony. Yes, I am familiar with the skewer method and I will use it. I wonder about the yellow pseudo bulb though. Someone said that it could be due to another issue. What issue?

[camille1585]

Do you have a photo of it? That would help out a lot.

[Otis226]

Originally Posted by greenpassion

Thanks Tony. Yes, I am familiar with the skewer method and I will use it. I wonder about the yellow pseudo bulb though. Someone said that it could be due to another issue. What issue?

Good question. I would also be interested in knowing.
Tony