Reposted from: The thread "Cymbidium Leaf Markings" in Orchid Insect and Disease Control-Part 1

fano16 said:Dear All.
my cymbidium going very badly. Is a 5 years old plant. Just repot 1 month ago. Leaves continue to get yellow and in 1 or 2 days and then fully brown. No linear necrotic marks.
Can it be dehydration? can it be lack on fertilizer (unfortunately never given).
Please let me know if there's a way to save it, I really need it.
Many Thanks

@fano16

Could you please let us know how often you're watering and what media you used? I'm also concerned by what appears to be white stuff on the leaves in the top centre of the photo (although it might just be a reflection, since it looks like you recently watered it).

In my experience if the leaves are yellowing and dying from the tips first (along with the pseudobulbs shrinking and becoming wrinkly), it's dehydration. If they start browning/dying from the bulb end and suddenly collapse, it's rot from overwatering. It looks like the former in your case.

Here's the problem, though - dehydration symptoms can be caused by both under and overwatering. If the roots have been severely damaged in the repot or have suffocated and died due to overwatering, they'll no longer take up moisture and so the symptoms of dehydration will appear.

Another factor is that certain species and their immediate hybrids absolutely hate being repotted (i.e. tracyanum will sulk and appear dehydrated, whilst sanderae will slow its growth to an absolute crawl for the next year).

The bulb at the front of the photo (with the brown leaves in the centre) is almost certainly going to go leafless. Hopefully, though, we can sort out the problem and stop the rest losing all their leaves (particularly that new growth at the back right).

Australis, you know Cymbidiums better then I do, that is for sure. Additional photographs and detailed cultural information will certainly help but I think what I am seeing is a division that is too large!
What I think I see are a few bulbs, back left with what appear to be two newer growths. Then just about everywhere else I think I see older leafless bulbs. Lastly up front center these floppy leaves seem to be the natural sloughing of leaves on an older bulb.
Instead of one division, I would have turned this into 3 plants.
#1 back left maybe two older bulbs plus two new leads.
#2 central mass of leafless bulbs.
#3 the front facing leaves and its bulb plus an additional bulb or two.
This would have yielded three divisions instead of one plant. Each could be in perhaps a 5 or 6" pot.
With three divisions, more "eyes" might pop and if one section is in trouble, it will not be able to drag the other bulbs down with it! What do you think??

Thanks for the comments, Bill. It depends on how many of those backbulbs were leafless to begin with - if the bulk have lost their leaves since the repot, then it's definitely a concern. I probably would have split it into two halves originally, assuming most of those weren't backbulbs. We also don't know how many of those bulbs are still viable.

@fano16, do you remove the dead bulbs? You can check to see if a leafless pseudobulb (backbulb) is still alive by squeezing them. If it is firm and solid, it is alive and can be used by the leafy bulbs or may produce new growth. If it is squishy or feels hollow, it's dead and can be removed. It will likely pull out easily in that case.

Another thing I would do in this case is to remove a few live leafless backbulbs from the right, peel off the leaf husks (the easiest way to do this is to split them in half) and pot them up individually to try to strike them. This would be a backup in case the mother plant dies (I did this with one of mine that I thought I was going to lose; thankfully, the mother plant's decline halted and it has now put up a new growth, whilst the two backbulbs have both struck as well!).

you're really great guys!! Many many thanks for the comments provided. i love the way you've analysed what sent.
Let's add more information then. I water it once a week. I mist the leaves and then allow water to get directly in the clay pot (not much water to be honest). For sure between a watering and the other the top of the pot is dry (3cm) (I always put a finger in to see if wet or not).
Leaves start becoming yellowish form the top middle part and then become fully brown, I would say this happens from the tip down through the bulb and not the other way round. I re-pot it trying to stop what here above described happening. I did not remove the dead pseudobulb (backbulb) with the fear to damage also the few live ones remained. I've kindly removed with the finger the dead roots, and left space for new soil to take place. As you've forcasted, bulb at the front of the photo is already "gone". Brown pseudobulbs in the middle of the vase are not firm and solid, and instead if I touch them, seem to be hollow.
Many Thanks to you all !!!!!

You need to water the top of the media, not the new growths or leaves.
Misting is not really beneficial. It can really create more issues then it solves.
Water the plant really well so it really pours out the bottom. You need to get the media really moist so that the roots within get moist. Then let it go almost bone dry and water again.

It sounds like you're underwatering. Cymbidiums use the leafless bulbs as moisture reserves, so the fact that so many have shrivelled up and gone hollow (i.e. died) indicates that it's seriously dehydrated.

As Bill recommends, water it thoroughly and allow it to dry out before watering again. Depending on your conditions and the media used, this will probably be a few days. Don't be tempted to let it soak in water or overwater it, as this will likely kill the remaining roots.

What media did you use when you repotted it? You mentioned you left space for new "soil" - did you use a potting mix, or Orchid bark? Cymbidiums are semi-epiphytes and cannot survive in dirt/soil/potting mix.

@Big Bill, @Australis, again many thanks.
I'll try to water it more frequently, hoping there's still a chance to keep it live.
I've changed now also its position now allowing more light but (not direct sun light)(N-E exposure). I've used Orchid bark to re-pot it; while doing it, I found soil inside, that I gently removed. I'll try to use also food for orchids once every 3 weeks. I've never don it before.
Many Thanks

You found soil because many people grow these as semi-terrestrial plants using potting soil or peat moss in their mix.
But Cymbidiums are one of the few orchid types that like heavy feedings. Vandas and Catasetinae are two others.
Your very welcome!!

You're welcome! We're happy to help.

The "soil" you found inside may have been the previous broken-down media. Often Orchid media will slowly break down over several years. This results in less air flow around the roots and typically traps more moisture. That's probably why your infrequent, limited watering didn't immediately cause dehydration - the broken-down media wasn't drying out anywhere near as quickly as the new bark. I'm guessing the problem accelerated once you repotted it?

Another tip is not to use fertiliser on a struggling plant. Hold off until the plant is stable.

Regarding light - Cyms like a lot of light and depending on your location and time of year, they can even handle full sun. Where I am in Australia they will suffer leaf burn if they get direct sun during summer, but otherwise can handle (and benefit from) full sun in winter.

Cross-posted with Bill. He raises some good points. Personally, I wouldn't recommend soil or potting mix.

Cyms are often thought of as semi-terrestrial because most of the show Cyms are bred for upright flower spikes. This can be traced back to just a few species that grow in leaf litter or well-draining sandy soils on the ground (i.e. Cym. insigne). Many of the species are epiphytic or semi-epiphytic, though, such as the well-known tracyanum. Even Cym. insigne can be grown as a semi-epiphyte due to its requirement for excellent drainage and good airflow.