What's wrong with my leaves on this Hollywood Dendrobium? - Orchid Board

Cinderella · #1 12-05-2010, 03:58 PM

Hi,
I bought this plant with an identical one (that is blooming now) about 3 years ago. It doesn't look so good now.

What is wrong with the black round spots on the leaves? In the last pix, you can see that there is new growth in the middle which is bright green. But this is not blooming. I am worried maybe it is some virus that I need to get away from my good blooming plants. One more clue is that I did move it away into a more indirect sunlight. Any help or suggestions? Thank you!

camille1585 · #2 12-05-2010, 05:57 PM

I don't think you need to be concerned about virus, the spots look more like they're bacterial/fungal.

Did you move to more indirect sunlight from a brighter or dimmer spot? Other than the spots it looks ok, so maybe more light would encourage it to bloom. Up until moving it, was it getting the same conditions as the one that is currently blooming? Hopefully once that new growth matures it will bloom for you.

Cinderella · #3 12-05-2010, 06:25 PM

Quote:

Originally Posted by camille1585

I don't think you need to be concerned about virus, the spots look more like they're bacterial/fungal.

Did you move to more indirect sunlight from a brighter or dimmer spot? Other than the spots it looks ok, so maybe more light would encourage it to bloom. Up until moving it, was it getting the same conditions as the one that is currently blooming? Hopefully once that new growth matures it will bloom for you.

Yes, I did move from a south indirect yet long summer sun to an East window thinking maybe it was being burned. Both of the plants bloomed together last year in that south window. When I saw the black spots, I decided to move it to the east window where other orchids have loved to be. At that point, both of the plants were not in bloom. The -no dark spots- plant just went into bloom again. Thanks for your help.

camille1585 · #4 12-05-2010, 06:33 PM

Have the spots still been spreading? You may want to treat the plant before placing back with the others (it would probably like the higher light again!) As to the cause of the spots, have you been misting the leaves or leaving the leaves wet late in the day?

WhiteRabbit · #5 12-05-2010, 06:44 PM

my thought too, was perhaps the spotting was from water sitting on the foliage in cooler temps ...

Cinderella · #6 12-05-2010, 09:01 PM

Quote:

Originally Posted by camille1585

Have the spots still been spreading? You may want to treat the plant before placing back with the others (it would probably like the higher light again!) As to the cause of the spots, have you been misting the leaves or leaving the leaves wet late in the day?

No, I don't think the spots have been spreading. The newer growth that is difficult to see in my pixs look healthy and no spots yet. I do mist, infrequently, and yes, I could have left water on them but I'm not sure. I will make it a priority to dry those leaves.
What type of treatment would you suggest to use and where do I get it from?
Also, just thought of this. When I looked at that plant again, I felt one of the black circles and it seemed like it was indented. If that helps investigators on my case.

camille1585 · #7 12-06-2010, 04:20 AM

For the treatment I can't help you there, I don't know what people use in the USA. However since it doesn't seem to be actively spreading anymore you could try spraying listerine or cinnamon spray (home remedies scroll down to fungicide sprays)

Indented spots are also a sign of fungal/bacterial infections. The leaf tissue in the circle rotted and the cells collapsed, leaving the ugly marks.

Cinderella · #8 12-06-2010, 01:15 PM

Quote:

Originally Posted by camille1585

For the treatment I can't help you there, I don't know what people use in the USA. However since it doesn't seem to be actively spreading anymore you could try spraying listerine or cinnamon spray (home remedies scroll down to fungicide sprays)

Indented spots are also a sign of fungal/bacterial infections. The leaf tissue in the circle rotted and the cells collapsed, leaving the ugly marks.

Oh, that is a great link that you sent me. I think I will try some of those and keep it away from my other orchids. One other thing I noticed if this helps id what it is, is that I noticed a few clear sticky dots on the underside of the leaf. I am guessing this must be sap. I am wondering if whatever it is, is eating the sap of the plant.