Hi everyone, this is what the plant now looks like becase I have to be removing, so many stalks. I have tried removing the stalks and using cinnamon but this still has not work please help me because I don't want to loose my plants. They are very expensive where I live which is in jamaica. Thanks to anyone who is willing to help, I would really be greatful. Velleta

Hi again, just one more pic so that everyone can see what I mean, where my finger is in the picture that is where the new shoot came up and then turn black and just died. This is the second shoot from the same plant that this has happen to. Again thanks to anyone who can help. One more thing, I sprayed with mancozeb and malathion a few days ago after I realize the problem was present. Thank again. Velleta

Perhaps it is your potting mixture. Coconut chunks make a good potting mixture in some growing conditions, not so good in others. My impression is that in tropical climates you need a more arid mixture, one that dries quickly between waterings/rainfall.
Western Exposure? You need all day sun shaded by shade-cloth appropriate for how far you are from the equator.

Thanks Arthurm, so do you think I should repot? And what mix would you suggest? Velleta

Coarse bark and a little charcoal has worked for me. Continue to treat the fungal infection but it is also possible that your plants are suffering from a calcium deficiency. Calcium deficiencies can cause newly forming pseudo bulbs to turn black and rot. Make sure that your fertilizer has calcium in it and Google 'calcium deficiency and Cattleya.' there are websites that will describe this a lot better than I can.

Thanks greencurls, that was one of the possibilities I considered so I gave it Epsom salts. Ok I will treat and look into the calcim defficency. Thanks again.

I think its black rot and is difficult to cure.

Here's an article from American Orchid Society.

Jane

Here is a link that might be useful: Black Rot

Jane , oh my god!!!! I read the article and the pics that are there looks exactly like what is happening to my orchid. :( I think my best bet would be to remove it from it pot, and cut away all the infected tisse treat with cinnimon put it in a smaller pot and pray it srvives. I have two plants with these symptoms. So I will treat all of them. I hope I can help it to recover. :( thanks for everyones help and if theirs someone who know how to deal with black rot, I would be greatful if you cold shear the information. Velleta

Velleta, is it a affecting only new growth or is it spreading to the mature growth?

Terpguy, it also afecting the mature growth on one of them. :( velleta.

I'm going to open a can of worms here, but i.m.h.o Cattleyas are one of the most difficult and disease-prone orchids, especially if your conditions are not ideal. They are definitely not suitable for growing in bark in pots. The only ones I have that are still healthy are the ones I have mounted on plaques, put in hanging baskets or mounted on trees. We have a frost-free climate. If you MUST grow them in pots you will need to give them a regular soaking in fungicide/ bactericide. Or just grow easier orchids! Good luck. Ian.

Do you have hard water? I see a white film on your leaves and on the pot. I had similar problems until I switched to rain water. The build up from hard water was burning the roots and new growth. Can you put them out in the rain for a while?

I've grown my cattleyas in bark with no problem in the past (they are all in S/H now though). I think its a good study in what works for one won't work for another. I also don't have disease issues, though scale/mealy is an entirely different question.

Hi, I'm from Trinidad, just few islands away from you.

I hope it's not black rot that is affecting your plants. As Ian said cattleyas can be difficult. I have a few and most are quite prone to scale and mealybugs. I don't have much problems with hard-cane dendrobiums though, they do well in the Caribbean.

As far as potting mixes for catts and dens, you should consider using just charcoal or stone, or a mixture of both. Coconut bark does not dry as fast and tends to deteriorate quickly in the tropics. Also it attracts fungi which isn't good for the health of the plants.

I have a garden blog @ http://trinigarden.blogspot.com/

I agree catts are relly difficult. :(. I removed them from their pot and found the roots on the inside were TOAST all gone. I guess that was what was happening. To them no roots.the only healthy roots were the few on top. So I had to cut, and trim and treat then repot them to smaller pots. Hopefully this will help them to bounce back. I am much better with plals. Also I think I will also lengthen the time between waterings and I also use a lot of chatcoal this time. :). Thanks to everyone for your healp and sugessions. I even learn a few things I did not know. Personally I think I will stick to the phals much easier, again thank.everyone and if you guys have more sugessions as how to grow them I would be very grateful. It dosnt seem I am doing too good of a job. Velleta

I've had 3 plants develop black rot over a 20 yr period. It never spread to my other plants.

Never was able to save the plant. Spreads rapidly. It always began in summer as, what I thought was sunburn. Leaf would get burned (like many other plants) but would turn black and begin to spread. Even removing the leaf wouldn't stop it. Any new growths would turn black before they had a chance. It would spread along the rhizome killing off the older bulbs.

It always seemed to affect plants which seemed stressed. Something not quite healthy about them.

I have a Catt (Pontinara) which developed it last year starting with sun burn of a leaf. I've had this plant about 10 years, healthy, flowered each year up North. I decided to experiment changing the cultural conditions to see if I could stop it.

I cut cut and discarded the diseased bulbs. I then cut the plant in pieces looking carefully at each section to see if any part of the rhizome showed disease. I wound up with three decent sections each containing 3+ bulbs (this was a large plant). Potted each section separately in clay pots with rock. Every cut was sanitized with alcohol. Hung these pots under a tree in almost total shade. I also potted two small back bulbs which seemed healthy. These plants are not near my other orchids.

Five months later they are still alive. They are starting a few growths which look okay. I've noticed some black leaf tips and sliced that off. Plants are hanging in an area where I forget about them. So they've only been watered with rain. If I see any sign of black rot or spread of black on the leaves, I will call it quits. The reason I did all this was to see if a radical change in environment would stop it. Chemicals never worked in the past and I felt it was bacterial not fungal. It spreads so fast, you really don't have time to wait.

I think a stressed plant is the trigger.

I've grown all my Catts in bark. The majority of my orchids were Catts and only 3 developed it over the years. I still use bark even in Florida. I don't think growing in bark is the cause. Maybe heat, too much water or humidity, lack of air movement.

Jane

Jane I think heat is the cause we have had a VERY HOT summer this year. One of the hottest I have felt for a long time. And then the rains came and it poured every day so I think the sudden change and maybe my watering habbits trigered it. But let's hope it pulls through. Thanks again velleta.

Hi Velleta,

Have you had success dealing with the black rot? I just realised today that one of my catts has got it. I've now isolated it away from the rest of the plants, and will probably do some surgery on it in a couple of days. So far, 2 - 3 bulbs are affected. One is pretty much dead. All of them new bulbs. The old ones appear ok so far.

Also, I've read that its very contagious. I have another catt with leaf burn (or so it appears!) so im really nervous now!

thanks!

Hi Raistlyn, yes even though I cut and discarded the rotted section of the large Catt I lost it, but the smaller one I saved and now its putting three new shoots out. It a long fight but you have to cut all the infected tissue out TOTALLY spray with hydrogen peroxide and then dust with cinnimon also isolating it is good. The problem with rot is when you see it the plant is already on its way out , but if caught early you have a chance. I now pot my catts in just charcoal so less chance of staying wet too long some of them are already in the coconut husk so I can't trouble them as yet but I am planning to go stright charcoal. Also keep a watchful eye on the plant because even if it looks ok it can still go downhill. Its a matter of inspect, cut, discard, and cinnamon. Good luck. VELLETA

Thanks Velleta! Im hoping to save it - keeping my fingers crossed!

hi everyone i am from trinidad to and i do the same thing with the stone and charcoal

"Cattleyas" are really difficult. Depends on where you are and your growing conditions. Not difficult here! Coco-nut chunks came on the scene and they are a valuable addition to the array of available potting materials .

Not good for Cattleyas grown under shade-cloth in a climate subject to heavy rainfall at various times during the year.
Retains too much moisture. Cattleyas grown in glass-houses where the watering can be controlled fare much better.
The general rule is...the closer to the equator, the more arid the mix.

To be honest, I don't think coconut husk are the best choic when it comes to cattleyas( found out from experience) it hold moisture way too long and because its light weight you can't really judge when it needs water. I normally water my catts every eight to ten days and here its very hot and guess what I still got rot from it holding the water. I repotted most of mine in charcoal because the water runs right through and yet it hold just a bit for a short time so less chance of rot it dries quickly and within another day or two you can rewater, I am gonna start with four to five days and see. Catts are really difficult. But I guess when it comes to orchids, its a trial and learn process. Oh and BLONDY, some of my dens have started to get back new roots now I will be buying some to replace what I lost and now I know. STONES for den. LOL. VELLETA

I agree. I have come to realise that Catts are really not easy. I have a couple of hybrids that seem to do well for me, but for the most part, i find them hard to reflower and maintain. In winter here in Switzerland, it is way too cold for them to stay outside so I struggle to give them the temp drops they require at night indoors yet keep them dry but watered. Unfortunately for me, Catts are my favourites. Oh well...

Keep at it Raistlyn, you will figure it out eventually. My favourite are Lady Slippers. They are just awesome I had two and they both died here they are next to impossible to get so at the moment I have not replace them but I will and if I have to try ten times I am gonna get them to love me and my environment. So persistant is key, we all have one issue or the other with then BUT its so good to know we can all come here and exchange ideas, and tenique, tips and trick so one way or the other we all benefit and learn on our journey to having beautiful and healthy orchids. VELLETA.

The reason cats are difficult in Jamaica is the tropical lowlands Climate away from the higher places is much too warm for many hybrid Cattleyas..... many of them need a winter so that they can "decide" to flower in spring.
By winter, I mean a dip in temps, not a real winter with ice and snow.
Probably the easiest group are those that grow a new Pseudobulb in summer and then flower immediately rather than waiting for a weather event such as the pretend winter that occurs here in the sub tropics.

Perhaps you should only look at hybrids with ancestors that occur around the Caribbean and avoid those with strong influences for cooler climates.

This post was edited by arthurm on Sat, Nov 2, 13 at 23:29

I did major surgery to my infected catt yesterday but removing entire pbulbs and then dusting with cinnamon and watering with a fungicide. Time will tell if it manages to stop the rot. Alas, i think another epicattleya is now infected! It started with what i was sure was sunburnt leaves but now many of its bulbs are brownish and somewhat wrinkled. Would appreciate confirmation from someone. I would hate to have to chop this plant down.. It has such fat bulbs!
Really this black rot thing is making me regret taking my plants outdoors this summer...

Raistlyn I am so sorry but it looks to me as if your gonna have to remove all the bulbs that is black before it spreads ferther. Once they turn black you have to remove them. They will not go green again. VELLETA

Thanks for the quick response Velleta! I went to check again and all the pbulbs have some sort of brown/purplish colouring. Some are almost all coloured and some just slightly tinged. The newer ones look less coloured than the older ones. So, should I consider this plant a goner and dump it? The plant has new aerial roots growing and looks (still) far from dead!

im worried also that it might spread to my other orchids now. What a nightmare!

Ok I am not an expert but keep it away from the rest of orchids. Remone every black bulb( painful I know ) spray what's left with hydrogen peroxide. Repot it to a much smaller pot,keep in shade and water with phyton 27. And PRAY. That's the only thing left to do. Good luck. You could also water the rest of your collection with phyton 27 as a preventitive measure so stop it before it begins. I really hope it helps. VELLETA

I've had this happen to me a few times over the years. I have never been successful saving the plant until recently. I'm curious as to the cause. I know it is said to be caused by a bacterial infection but I wonder if any real research has been done on it.

When I moved a few of my plants from NY to Florida, one Catt was showing signs before the move. I cut off the infected bulbs and treated, but then I neglected most of my plants because there was too much going on.

The infection slowed but each new lead would show signs and I'd cut it off. After settling down at a new house, I worked on the plant and wound up dividing it into three sections. I needed to cut so much off it literally came apart. I potted each section of about 3 bulbs each and stuck the plants under a tree, away from my other orchids and forgot them.

Yesterday, I looked at them. They were dehydrated (no rain for over a month), they hadn't been fertilized in a year, but I noticed each bulb was forming new leads and roots. The plants were buried in oak leaves but appeared healthy.

I'm still not trusting what I saw, am keeping them away from my other plants but all three pots appear recovered.

So, I'm now wondering if - dehydration, oak leaves (change in pH) or just luck, seemed to work.

If these survive, it will be the first for me. I'm thinking it might not be bacterial or even fungal. I'm leaning toward pH because I have always watered with RO but these plants only got rain.

Any thoughts from those who have experienced what the OP is dealing with and any tips about what might 'really' cause it.

Jane

I have had an old cattleya plant for many years and split it when it becomes crowded. This year the sections look bad. Many leaves have turned yellow, a few have rotted at the base and old stems are brown and wet looking. They are in a cool greenhouse. Could it be cold damage or have I picked up a disease?