Black Spots Underneath Phal Leaves

[Kearneyweard]

Hello,

I recently acquired a phalaenopsis orchid and it was doing pretty well for a while. A few weeks ago the flowers started to wilt, then they all fell off, I cut down the spike, one of the leaves started turning yellow/brown, I cut off obvious rotted roots and planted in new medium (sphagnum moss), now there are black spots underneath the yellow/brown leaf.

The black spots are dusty and I was able to easily wipe them away with a cotton ball soaked with hydrogen peroxide. I'm now worried that my phal has something more serious. As I mentioned, I cut some of the roots but now I'm worried that I did it incorrectly. I sterilized my cutting device with a flame after every cut and I dabbed ground cinnamon on the end of each root I cut.

Thanks to an Orchid Board Member, I did notice that I had the medium packed too tightly and it was too high because it was covering the crown. So about two or three days ago I took a huge chunk of the medium out and now the orchid looks like it has more breathing room. I've looked at pictures of crown rot and I don't think that is it. Can any orchid experts explain what these spots may be?

**NOTE: I have ordered a smaller pot for the orchid and Physan 20, so now I'm just waiting for it to arrive.**

Here are both of the leaves. Only the one on the bottom is turning yellow/brown. *knock on wood*


Here's a close-up of the yellowing leaf. That blemish on the left has always been there. It looks like it may have gotten worse and may be splitting... Still not sure.


Here's a shot of the side of the yellowing leaf. The underside of the yellow leaf that is viewable in the picture is where the black spots were before I cleaned them.


Here is the back of the "good" leaf. I have studied it very carefully and have not found any black spots.

[Brooke]

Usually when you have a Phal leaf turn yellow from the stem out you have a bacterial infection where the leaf touches the stem. If this were mine I would pour some regular peroxide you keep in the medicine cabinet and try to stop it before it penetrates the stem and you lose the whole plant.

This is the same infection which causes crown rot but it starts lower and goes up the stem. If you had the sphag packed to close to the stem this could have created the problem when it stayed wet.

Brooke

[camille1585]

Yellowing that starts from the base rather than from the tip of the leaf is a clear sign that it is not normal leaf aging. I'd also guess that water got in the 'crotch' of the leaf when the base of the plant was covered, and started to rot.
I would remove that leaf, scrap away any rot on the stem, treat with hydrogen peroxide, then coat the area with cinnamon powder. With any luck you will have caught this in time. My sister recently 3 Phals to this, by the time she got worried about it the disease had aleady gone systemic in the stem.

[Kearneyweard]

Thank you so much for your suggestions. I have treated the orchid with hydrogen peroxide and a few days after, the leaf broke off when I was moving it. I dabbed the area where it broke with ground cinnamon, since it was exposed and vulnerable. It's been almost a week and the orchid is still looking good for now. I only have one leaf left but it has stayed green and looks healthy (I inspect it daily). Hopefully I have stopped the infection. The orchid still has a few strong, green roots left so I hope it will survive. Thanks again for the help!

Recent pictures:

[Irielicious]

Originally Posted by Kearneyweard

Thank you so much for your suggestions. I have treated the orchid with hydrogen peroxide and a few days after, the leaf broke off when I was moving it. I dabbed the area where it broke with ground cinnamon, since it was exposed and vulnerable. It's been almost a week and the orchid is still looking good for now. I only have one leaf left but it has stayed green and looks healthy (I inspect it daily). Hopefully I have stopped the infection. The orchid still has a few strong, green roots left so I hope it will survive. Thanks again for the help!

Recent pictures:

How is your orchid doing since you last posted???