Hello all and my thanks in advance for any help with this issue. This year on Valentine's Day I received a large, beautiful phalaenopsis orchid. Last year when I received a smaller one, I immediately dove into research about orchids and still managed to kill the poor thing. It had been potted in very tightly packed sphagnum and died of root rot.
Consequently, I vowed that this time around would be different. Right away I noticed that the lowest leaves on either side looked unhealthy. They were both withering and discolored to differing degrees, and the worse of the two has since fallen off. The other looks like it will be soon to follow.
Because of my previous experience with overwatering and root rot, I have been very careful not to overwater it and since day one have been watering very sparingly. Once again, it appeared to have been potted in sphagnum, but a video from a University of Illinois orchid grower said not to repot them until they finished blooming, so I decided to hold off. The pot it was in has terrible drainage, with only one dime-sized hole in the bottom, and despite it having been about a week since my previous watering, the roots still seemed to be wet, especially where they were pressed against the pot. This prompted me to stop watering it altogether and monitor it even more closely.
That leads to today. When the afternoon sun was shining on it just right, I noticed that it appeared to have dark spots on the leaves, mostly along the edges, which I was shocked I hadn't noticed before. It turns out, the sunlight was allowing me to see the shadows of spots on the undersides of the leaves from above. When I looked underneath, sure enough there was a plethora of dark spots there and even what looked like a powdery black spot or two closer to the stem on one or two leaves.
Suddenly realizing how bad things looked, I did some more research and decided that this was probably black mold. I was afraid of how damp the roots still looked and how they were starting to get little dark spots on them where the water was trapped against the pot. Most of the roots were still a very vibrant green, but I didn't want to take any more chances with the damp sphagnum.
So far I have removed the orchid from its pot, took out all the sphagnum (which was indeed still very damp and VERY tightly packed), and used sterilized scissors to trim away about 4-6 root segments that looked like they'd rotted through the vellum. Overall they looked MUCH better than the roots on my last orchid when I discovered they had root rot. In the middle where there was no airflow, the roots are yellow and pale but still firm, and all the outermost roots are a nice green except where the little spots had started to develop where water was sitting trapped between the root and pot.
Once I'd trimmed the bad roots and disposed of the sphagnum, I started washing the leaves with a weak solution of water with a couple drops of Dr. Bronner's baby soap per the suggestion of an article at myfirstorchid.com. Many of the darkest, blackest spots washed clean, but most of the spotting looked permanent. It also appears to be on literally all of the leaves. A couple of the leaves have started to split down the middle from the tip.
I took several pictures and before cleaning it, and after I was done I dusted the whole thing with cinnamon in case this is fungal. It's currently sitting like that while I let it air out and write this post. I plan to buy some Physan 20 Broad Range Disinfectant for it, and/or Truban or Terrazole. Maybe Aliette or Subdue, but I have no experience with any fungicides. After that I plan to put it in a nice orchid bark mix I bought last year but never got to use, but I fear for the worst. A lot of posts say to just throw the orchid away when it gets this kind of infection, but it's my only orchid and if there's any hope, I'd really like to save it. Many posts say to use sterile scissors or razors to cut away any affected leaves, but in this case that would be literally all of them, I think! I'm attaching the photos I took in case they help assess the problem better than I can. (If I were only looking at the flowers, I'd think this were a beautiful, thriving orchid, hahaha!)
Thank you in advance for any input and advice!
Phalaenopsis with dark leaf spots and powdery black spots (black mold?)
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