Single leaf yellowing?

[spinrah]

Originally Posted by aliceinwl

At cooler temperatures infections can be an issue. If the top dressing of moss is staying moist it could be causing problems. My Phals are in bark at similar temperatures. They dry unevenly (top gets dry before the bottom). I just wait until the bottom is dry as well before I rewater.
Uneven drying doesn’t seem to cause a problem. I think that having things quickly dry on top around the stem is beneficial especially if temperatures are on the cool side.

It could just be natural aging of the leaf. But, I’d carefully inspect the stem for any indications of trouble and get rid of the moss.

I never thought about the trade-off between uneven drying and temperature. Hmm, you make a good point!

Ok, you guys have convinced me to remove the moss.