Old dendrobium black spots etc.

[Celtic100]

I noticed today that my very old dendrobium has some strangeness going on with one of its leaves. Purchased in 1997 and has bloomed with tons of flowers over the years. In the last few years, it went through some orchid hell (me) but this year looks to be revived. It sent up a new flower shoot late last month or so but lately that growth seems to have slowed down. Today I noticed one leaf sort of yellow on topside. I removed it and when I looked closely, it had some strange stuff on underside. photo explains better. Any thoughts?

[Paul Mc]

I've been seeing this on my Dendrobiums lately. It was suggested that the silver coloration was actually a mite or something. I started using a cinnamon extract, dish soap and water spraying weekly. While it seems to stop for a while, I have recently noticed that other Dendrobiums nearby have this same issue now. Does the silvery area feel like there are tiny nubs all over in the leaf? Mine do!

[Celtic100]

How strange for your dendrobiums to be all of a sudden showing this "stuff". I have never seen such an anomaly on this orchid. It's usually very tough. I am thinking of repotting it and seeing what's going on with the roots - or seeing if I can see anything under the medium. The affected leaf does seem to have a rough texture - I don't see any sign of it on other leaves. I have looked at virus pictures - but can't really tell if this looks like a virus. It is a very small dendrobium and the only one I have. I don't see anything on my other orchids (4) and am hoping they don't pick this up. Has your treatment stopped other leaves from becoming affected? How is the mixture comprised? Thanks for input.

[Paul Mc]

My mixes are a Repotme Dendrobium mix and this spring will be my repotting season (oh, I don't look forward to that long haul, lol...). I'm fairly sure it's not a disease or bacteria as the mix I used repeatedly for weeks in end seemed to stop it. But after using it for about 4 to 5 weeks, I stopped and it seemed fine. Then this winter, it started up again. I'm wondering if the issue may have been eggs in the medium that I didn't get. Sigh... Hopefully someone with some input into our situation can chime in and confirm or deny my hypothesis on the issue and give us good direction.

[Paul Mc]

BTW, only the Dendrobiums in the same window are showing signs of it. It was more like get the course of a few weeks I noticed something happening, but east until last weekend I recognized the look of it. I've started spraying again until a better solution comes along, lol...

[Celtic100]

Hmm - yes, hope someone can give some insights into this. Glad to hear you don't feel it is a disease or bacteria.

"I've started spraying again until a better solution comes along". I am curious as to what the mixture you spray them with is comprised of. I haven't got a clue about making a solution for spraying w/o a little advice. I'd kill it for sure!!

[Paul Mc]

LOL... It's a simple recipe. A little bit of cinnamon extract, 10 drops dish soap, and fill the rest of the container with tap water. I just use a cheap small spray bottle from a hair salon store.

[marcecarloh]

i´m not an expert but a few years ago I had the same problem with my dendrobiums so I took them with to and expert and he said it was definitely mites, in my case were I live they where red mites. I used a white napkin to clean the underside and I saw very tiny orange spots that were the mites

[Paul Mc]

I did that with mine, with a white paper towel and found nothing. Then I thought if they are silver it might be hard to see against white. I then used a black shirt and still nothing. But I agree, all my research and suggestions have indicated that mites can be silver as well. Guess I just keep on keeping on, lol... In a side note, I bought a systemic mite killer today, so will be mixing it with my watering water for those plants now, and those in the vacinity.

[Celtic100]

I think I'm just going to transplant this little dendrobium -- separate the bulb that has the sick leaves and toss it, and keep the other 2 bulbs which are healthy. I'll keep my eye on this thread for thoughts that others may have. Good luck going forward and thanks for your input.