Cymbidium leaves dying from infection
 

I’ve got two Cymbidiums that, once upon a time, were one plant. Ever since I first got them in 2017(?), there has been some weird leaf spotting and eventual death. It starts as mini black or brown speckles at the top of the leaf, then a large black spot with bruised edges and finally, the leaf goes brown and dehydrated from the tip down and dies. It starts with one leaf then spreads to the rest in its leaf cluster. Towards the end, it spreads to the next oldest cluster and continues the cycle (I’m not sure what they’re called). This is a very slow process, weeks to even longer. I think I had a couple leaves with the marks that lasted a year? I’m really not sure what is going on with these guys but I really don’t want to lose them. I’ve put a lot of effort in to keep them alive. I’ve attached several photos that show the marks. The big one with the flowers is the original plant and you can see a spot on one leaf and another that is browning. That pic was taken January of 2018. The two little babies are what it is now and show it’s current condition.

Environment and Care:
The Cymbidiums live with several Phals, none of whom have ever been affected, and recently a Brassia and a Paph, both also unaffected although the Paph is too new to tell. They get watered often enough to not fully dry out but also not saturated all the time. They get fed with Miracle Gro acid lovers food and misted daily. They get a little morning sun then decent indirect light the rest of the day.

A Little Health Info:
These guys are baby sized now because they suffered from some serious root rot (basically no roots for one and only one for the other) but now have very strong root systems and are showing new leaf growth. They haven’t flowered in a year or two which is likely due to bad lighting and the root rot.

I hope I’ve explained everything well. Thanks for your help!Attachment 155746

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First, Welcome!

Most of the browning of the leaf tips is the sort of thing that is caused by an excess of fertilizer salts that tend to concentrate at the tip of the leaf, especially with inadequate moisture. The one black spot could be something fungal but it looks dry, likely old damage and so now harmless.

What medium are you using? Cyms like to stay on the damp side (but with air), small bark is an ideal medium. Also... if you are growing them with Phals, the overall conditions may not be what the Cyms want if the Phals are healthy... Phals are warm-growing low-light plants that need lots of air around the roots. Cyms are cooler-growing high-light plants than can stay considerably wetter. So if you dry out a Cymbidium like you need to do for a Phal, the Cym will be staying 'way too dry. You can have them on a similar watering schedule if you select the media to give each what they want... for instance, use large bark for the Phals and small bark for the Cyms. With the same watering schedule, the Phals will dry out and the Cyms will stay damp (as they must do).

Where do you live? (That helps in understanding what conditions you might be able to adjust)

Thanks for the quick reply Roberta! I’m using bark (pine I believe) that’s about 1/2” in size or smaller and sphagnum moss to help keep it moist. I might have some volcanic rock in there but I’m not sure. I water them more often than I water the Phals especially since they are so much smaller. I could probably water a little more often but that’s what caused the root rot in the first place so I’m a little hesitant. I probably let them dry a bit more than I should because of that. I live about 50’ from the Chesapeake Bay so it would be a bit more humid except that we keep the house humidity a little dryer which is why I mist frequently.

I’m not sure that the browning is from built up fertilizer because I didn’t get serious about proper care for my orchids until last year so all the browning up till now hasn’t been affected by fertilizer. Do you have any idea how to treat it if it’s is fungal? I’ve tried cinnamon but it didn’t work.

It's probably not fungus. My first thought was you're not watering enough. And they would probably prefer a lot more light. If you had a spot outside they would prefer that when it's not freezing.

I don't think that there is an active infection. I agree with ES that not watering enough is the big problem. What caused root rot before I don't know, but Cyms need to be damp (but never sit in water - pots need to be very well drained) Cyms should definitely should be outside unless it's freezing. Even little ones should be fine down to 40 deg F and likely lower - mature plants can tolerate 32 deg F.

when you say the brown spreads to the other parts of the growth are you referring to the same leaf or the psuedobulb they are growing from? if it is just the leaves dying i would not worry about anything i see happening. if the bulbs are dying then there is something wrong

i only grow warm cyms and i grow them all outdoors and in a mix of huge lava rocks, charcoal wood, #4 perlite, leca, broken pots and some peat, a handful of sand too, just for flavor :)
but leaves on mine get all kinds of those marks on them

My Cyms live outside, winter temps can get just above freezing. They're quite wet all the time. Small bark and perlite. They get almost full sun (I have 40% shade cloth over them because my yard is really bright in summer but with any trees to shade the noonday sun, they would not need anything) Ugly leaves are quite normal. Old leaves get shed just in the course of nature.

It might be fertilizer, or infrequent watering, as others have suggested, BUT...

Seeing that you are 50 feet from Chesapeake Bay, I am wondering if it is water quality. Does your water come from a municipal supply, can you get a copy of their water quality report? If available, total dissolved solids data (or electrical conductivity, same as specific conductance) may be helpful. Or, are you on a well?

I was thinking dissolved solids damage before I read the other replies.

Maybe, but I have not observed Cymbidiums to be particularly sensitive to water quality. Mine isn't too horrid, but lots of people in southern California grow Cyms with tap water that could be considered "liquid rocks" ... like 500-600 parts per million TDS (mostly calcium carbonate) Leaf tips tend to get ugly at those levels, but the plants grow and bloom quite well. Now, if the TDS has sodium rather than calcium as the dominant cation, that could be a different story entirely. But the OP is growing other orchids such as Phals with no problem. Cyms just aren't going to do well under Phalaenopsis conditions.

So I'm glad no one thinks this is an infection! I've definitely basing things more off the Phals so I'm gonna change that. I've started watering more. I've also put them on an east facing window sill in the corner. They get good light there. My only worry is it might be too much light. It's mostly direct light for most of the afternoon. One gets more light then the other. I'm thinking that as long as I keep them moist it should be ok? I'm also going to feed less. I've been feeding every time I water but I'll cut that in half.
DirtyCoconuts, the brown spreads down one leaf then the next but it is one bulb at a time and the blubs are unaffected.