Monnierara Millenium Magic - update!!
 

Hi everyone! :waving Here's an update on the millennium magic I posted about earlier this summer (thanks for the advice). So I purchased this one back in April and it looks like it never went dormant and was already in full swing. It grew another growth and boy it got huge!! The leaves never got quite as large as the original pseudobulb... weird. Well the leaves of the original bulb are yellowing rapidly and a few have fallen. Everything I read makes me think it's doing its normal end of season slowdown. So does this mean I should start slowing down water and fertilizer or should I wait for the new growth to slowdown too? Dare I hope that a spike is on its way? Lol. I also have read that this type doesn't always go into full dormancy.

Idk why it wouldn't let me link:
Monnierara millennium magic safe to repot?

The leaves on the new growth don't look right. The shortness and the yellow marks on them point to an issue. Not sure if it is a disease or cultural issue - hopefully someone can explain it.

Are there yellowish marks on on the new leaves, or does it just look that way because the plant is backlit?

I think the old growth is simply losing its leaves because they're old. The new growth isn't mature, so continue watering and fertilizing heavily.

No it's got yellow stripes. It's been looking yellowish since it started growing. I think it's the medium that's too degraded. It also got too much direct sun, if didn't start greening up till I moved it to a bit more protection.

People recommend feeding these extremely high amounts of fertilizer when making the new growth. If you haven't been doing that, it could account for yellowing leaves and unexpectedly short leaves.

As to what is extremely high, I've read between a teaspoon / 5ml and a tablespoon / 15ml of 20-20-20 fertilizer powder per gallon / 3.78 liters of water at every watering.

Yellowing new leaves is usually due to deficiency in nitrogen, magnesium or iron. Your plant looks nitrogen deficient.

It should tolerate direct, hot Florida sun if watered enough. I have seen Fred Clarke's talk on these. He shows photos of plants in habitat in the tropics in full sun, growing exposed on telephone poles, house walls and fences.

Wow. Guess they really are fertilizer hogs! I've been using the feet treatment I use with other orchids lol. Well, I'll increase fert and see if it helps. Moved it to a brighter location, chasing the ever shifting sun pattern (house blocking it now)... or is it too late for this year?

Florida has good sun and it stays warm late in the year, so it may still be fine.

Thanks everyone for your help. Let's see how it goes in a month!

I would slow down on the fertilizing and watering (not stop) Fred Clarke of Sunset Valley Orchids recommends a fertilizer rate of about twice what you'd use for other orchids during the summer, but right about now use pretty much what you use on the rest of your orchids. I would not change to a summer regimen now. It's not summer. You can keep on watering (just perhaps a little less) for another month or two. But if dormancy hasn't started by the end of December, stop watering anyhow and "encourage" dormancy. Check out Fred's culture notes.
Sunset Valley Orchids - Catasetinae Culture