This can happen when either a new leaf comes through and the older leaves
then start to die or it could be crown rot.

If everything you have stated is correct it could be that a relatively new
leaf has started growing or a new one is in the process of coming through.
The new leaves use the old leaves resources when they grow.

You didn't mention anything about new growths.......are there any?

"rmxrm" wrote in message
s.com...
I have a phal that up until last week looked as healthy as can be. New
spike, old spike with new side shoot, leaves green and trugid - very
nice. This past Wednesday the lowest leaf started to turn yellow all
over and today it is bright yellow - still turgid but very yellow.

Climate where the orchid is growing has not changed since I got it
several months ago. It is watered every Saturday morning. No bugs that
I can see. No crown rot that I can detect. It never has wet feet.

Any ideas what is going on with this orchid and what if anything should
be done with it?

Thanks...
--
rmxrm
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