Cuitlauzina orchid is not healthy!

[Saladmex]

Hello, my name is Carlos, and I'm new here. I live in zone 10a, Southern California. My Cuitlauzina Pendula, and Puchella that are not happy. Both have no roots, and are shedding leaves, down to 2 each. All my other orchids are doing really good. But I also have this really bad mite problem. They move slow, are red, but don't ever produce silk or threads. It's weird. They always come back, and it sucks.


I currently have them in a large tank where temperature max is 88F, and minimum is 70F, with an average of 80F-83F in the day. Every morning I spray them with RO water, to increase the humidity. The max is 67%, and slowly goes down to 10% by the end of the day. Throughout dusk through dawn its around 15-20% I thought this was good, but I'm sure that's what made my Cuitlauzina Pendula to get a rotting pseudo bulb. I just cut it out, you could see it on the bottom left of one of the photos.

Using a light meter app on my phone. They lighting is 5000 lux for the plants directly under the light, around 3,000-4,500 lux to the right or left of the ones under the light.[[This is where C. Pendula and Pechulla are]]. I usually keep the light on for 11 hours.

The media of these plants are in 3 parts of medium fir bark, 1 part moss, and 1.5 parts expanded clay pellets. With a humidity cap on top.

I would like to hear your critical review on what I am doing wrong, and any recommendations or suggestions for my cultural practices.
I am most concerned with the mites, as well as what medium I should use to encourage root growth for my Cuitlauzinas.

[King_of_orchid_growing:)]

I'm gonna be very honest here...

Those don't look like they're gonna stand much of a chance of surviving.

You can try to save them, but don't expect much.

The humidity has got to be much higher than 20% to even get the plant to think about producing roots on the new shoots.

You could try mounting the orchids on a piece of cork and place moss underneath the plant, then place the mount and the orchid in a tray full of wet moss. See if that will make the humidity go up to at least 60%.

When the humidity goes up, the spider mite problem may also go away.

[Roberta]

I'm not familiar with Cuitlauzina pulchella, but I grow C. pendula outdoors in coastal southern California. I grow it in a plastic basket with small bark and some perlite. Pomona has a rather different climate, being much hotter and drier. (I know, I spent about 25 years of my life there...) However, I wonder if you are getting adequate air flow in your tank. If you can create an outdoor shade area with misters (on a sprinkler timer) or a fogger to get the humidity up (focus on the morning, if the plant absorbs water early in the day it is better able to tolerate the hot afternoons) ,it may actually benefit from growing in a less controlled and confined environment, with natural sunlight (plenty of shade cloth, of course) In winter when temperatures may go below freezing at night fairly frequently, you will need to protect it a bit, but until then, try growing it with nature's sunshine, breeze and day-night temperature variation.

The really shriveled plant may not make it but the one in the first few photos looks to me like it has a very good chance of surviving. I went through a "rootless" stage too, and it came back nicely. New growth makes new roots.

You could use a plastic pot, and add some sphagnum to help maintain more moisture, but this plant does benefit from a wet-dry cycle. (I have found that the spikes, while pendant, do come out of the top of the plant so the basket is not really necessary)

[DeaC]

This is a cool-cold grower and I think your overall conditions don't suit it. Check out Internet Orchid Species Photo Encyclopedia,a very informative site. The blooms caught my eye a long time ago but after reading their requirements I knew I'd fail to grow them. Good luck.

[Roberta]

"Cool" is a relative term. Mine get overnight winter temps near freezing, but frost is less common where I live than where Saladmex lives. (And in both cases, it warms up as soon as the sun comes up) My summers go to 90 deg F. fairly often, above that more rarely but it does happen. Saladmex gets summer highs of 100-105 deg F fairly often (hence the need for more shade, the margin for error in keeping leaf temperature below the burning point is smaller). In both my area and inland the nights are relatively cool in the summer (and that is why we both should be able to get away with it.. I certainly do. My overnight summer lows are usually below 72 deg F, inland might be more like 75 deg F) My overall RH is somewhat higher than inland, but by giving lots of water in the cool of the morning (and evening in the hottest months of summer) the effects of the low daytime RH are mitigated. (OK, I am a "What can I get away with?" grower, but manage to get away with a lot... one learns tricks to push the envelope.)

[King_of_orchid_growing:)]

I have not found any Cyrtochilum to be problematic at the temperatures that Saladmex mentioned. This genus of orchids are pretty sturdy if they were healthy to begin with.

I don’t really know why they are only found in high elevations in the wild. The limits in habitat range might not be temperature related. It might be some other factor.

[Roberta]

Originally Posted by King_of_orchid_growing:)

I have not found any Cyrtochilum to be problematic at the temperatures that Saladmex mentioned. This genus of orchids are pretty sturdy if they were healthy to begin with.

These in question are Cuitlauzina, not Cyrtochilum, though the same principles do apply. Who knows, they may all get lumped into Oncidium...

[King_of_orchid_growing:)]

Sorry, read incorrectly for some reason.

Yes, the temperature ranges should still be ok for Cuitlauzina.

[estación seca]

Welcome to the Orchid Board!

I don't think the tiny red arthropods are the problem. If you can see them, they're not spider mites. There are predatory mites that eat spider mites.

I think your problem is lack of humidity combined with high temperatures. Some plants can tolerate this with increased watering, but many can't.

[Saladmex]

Thank you yall for your imput!
Ive done some cultural changes.
I put a screen under my lights. This decreased the overall temperatures of the tank by 5 degrees. Still bright tho. I also have been putting an ice pack above the cuitlauzina orchids at night to decrease the temperatures at night. Apart from that ive changed the type of quality moss for all my humidity caps to high quality. The lowest humidity stays at 15% at night its now around 47%
Thank you estación seca! Ive been trying to kill those "bad guys" for such a long. time. My cuitlauzinas were doing so good, but i think the solution of my pesticide was too harsh for them one time, and caused them to die off a bit. What a novice mistake.

Ill keep you all posted if the orchids make it or not!