Trouble with my Cattleya

[sneep]

Hi, I am fairly new to growing orchids (a year and a half now?). I currently have four orchids, a dendrobium, a phalaenopsis and two young cattleyas. All are doing well except for one of the cattleyas. Both catts were purchased inexpensively at a big box garden store (which I know do not have the best reputation!). They came in two inch pots and looked healthy enough. So I thought I'd give them a try. After bringing them home I followed the instructions on the packaging and repotted them into slightly larger pots. Though they have showed no new growth, all seemed well enough until about a month ago I noticed that one of the two was developing spots. These are dark and almost indented compared to the normal surface of the leaf. I have pictures of three different leaves (in three different states) from the same plant. They should show up below as attachments.

Like I said, I have three other orchids which are all doing well, including the other catt that I bought at the same place and at the same time. My first though was that it was getting too much sun, hence the yellowing leaf. But the other catt is in the same window with no such issues. So I'm thinking this one might be sick in some way. But if so I'm not sure how to proceed from here. Do I removed the bad leaves or is there some kind of treatment that can be applied? I'd very much appreciate your help as I'd love to be able to save this little one. Thanks so much in advance! -Ken

[kmarch]

This looks like a fungal infection. If this were my plant I would:
1) cut off dead leaves and/or infected parts of leaves
2) treat with a good fungicide
3) increase air flow in growing area
4) reduce humidity (if possible)
5) make sure infected leaves are disposed of away form growing area.

Other members might have other helpful advice too.

Good Luck!

[jerrymeola]

This is either a fungal or bacteria infestation.

Fortunately the rot has not spread to the pseudobulb and can be cut off.

When the rot reaches the point where the leaf begins to grow out of the pseudobulb it would be too late. At that point the infection has gotten into he plant and its root system. You will seldom save a plant when it reaches that point.

The first picture also looks like a pest eating on the leaves. If it had been pests it would have stopped there and you would not have had to do anything.

When it expanded to the second picture that is the definite sign of infection and should have been cut off at that point. The third photo shows the leaf about to die and fall off. The plant is removing the infection before it can get to the roots of the plant. Often you are not so lucky and the infection would keep spreading.

This plant may have survived without your need to do anything, but it is a good learning experience.

[sneep]

Thanks to both of you for your advice. I have trimmed the infected leaves and treated the fresh cuts with cinnamon as I have read to do. So I guess it's a bit of a waiting game from here to see how it does in the longterm. But thanks again, I appreciate the help!

Ken

[missann]

Also I would isolate it from the other plants, so that fungal spores cannot become airborne and get on your other plants. I just bought a product from Fred Myer that is called "Indoor Pharm" that says it keeps fungal spores from becoming airborne, but I have not yet tried it on a cattleya. So far it seems ok for my cymbidium though. You can construct an inexpensive isolation/plant hospital by obtaining two clear tupperware containers and putting them one on top of the other so it is like one huge container. Then just duct tape one side so that you can easily open it like a box. You can prop it open with something, or you can just cut some holes in the top. I would highly reccommend taking the plant out or opening the lid completely at least once a day so that it can get some fresh air. Oh-but most importantly, I wanted to ask you if the spots started out yellow and then turned black. When the spots are yellow, can you see them on the underside of the leaf as well? Do they go all the way through? If so, you should test it for virus.

[sneep]

Thanks for the info! I'll have to look into some kind of way to isolate that Catt until I know all's well with it. As for the spots, they definitely started brown/black, not yellow. However I am not sure if they showed through the back. Sorry I can't be of more help with that. Thanks again!

[kmarch]

I don't think it's a virus. It doesn't look like a virus.

[brookn]

I don't think it looks like a virus. I would treat it with the cultural conditions that it needs, and I would not worry too much about quarantine. Simply placing it away from the other plants should take care of it. Try some cinnamon spray after you water it also (don't spray the roots unless they are showing signs of fungus) Here are a couple of links for you:

The Best Stuff Ever!!!

Skewer use for watering of orchids

AOS | Cattleya