Monn Millenium leaves yellowing while blooming?
 

I’ve had my millennium magic orchid for about 10 months and am a beginner orchid caretaker. Unfortunately this orchid suffered dehydration (due to me being unsure of when I could water and how much to water again) but other than that seemed happy.
About 9 days ago, my first flower spike started developing and seems to be growing happily.
However on the psuedbulb that isn’t flowing, the leaves are turning yellow and dropping.
What am I doing wrong? How can I save my orchid? :(((((

Only the bottom two leaves are yellowing, right? And the newest leaves remain nice and green, right? If that's the case, then probably nothing to worry about. Just keep watering as you had been before ----- and avoid overwatering ...... because overwatering or waterlogging/drowning of the roots can lead to root death and dehydration too.

Yes it’s only the bottom two, it all happened rather quickly though which is what started to worry me.
And now the bottom leaf on the bulb with the flower spike is starting to yellow...

This plant is a catasetum and at this season, in the northern hemisphere, it is going into dormancy. The new spike will develop using nutrients from its parent pseudobulb, which will eventually drop all its leaves. Watch for a new growth to start then, at the base of the bulb. That will be the time to repot. Don't worry about the extra growth that has already turned yellow; it is dormant. Meanwhile, back off on the watering, as these plants need a dry period during dormancy.


Have you read about catasetum care on Fred Clarke's website? He is the guru!
Sunset Valley Orchids - Superior Hybrids for Orchid Enthusiasts

Fish mom! In your opinion, should you always repot upon finding a new growth for all orchids or just for catasetums? I have always heard wait for new roots but I have a few Catts that have all spring new growths at the same time and just want to make sure I shouldn't be repotting them already?!

Catasetums are different. I like to repot my catasetums as soon as I see the new growth, so I can orient the plant so that the new bulb will grow as upright as possible. I do it before the new roots have grown much because they are VERY brittle and I don't want to damage them. This is all before regular watering begins.

Look at the Sunset Valley site fishmom gave above. There are detailed instructions for these plants. If you sign up for the newsletter at the SVO site you will get a quarterly E-mail telling you what to do with Catasetinae at that time of the year.

Thanks ES! I recently signed up for the newsletter but wasn't exactly sure how often it came out or what all it included!

Ahhhhhh! Thank you fish mom! Idk how I didn't notice your post last night and only ES's BUT! That makes sense! I will definitely have to do some research with SVO though!