Phalenopsis roots are turning black at the stem

[pottedlavalamp]

Hello everyone,

The stem of my phalenopsis is rotted about two thirds of the way up. Is there any way to save the plant? It appears healthy and I have only just noticed because it is putting out a flower spike. I realised the base of the roots are black. I thought the stem was just covered in left over dried leaves but have realied the entire stem is dried out.

I have attached some photos of the roots, the plant stem, and the entire plant.

Thank you for reading

[Roberta]

First, Welcome!
The bottom of the stem probably is rotted, and there are likely a bunch of rotted roots down there due to broken down medium. However, the upper roots (mostly outside the medium) look fine. (I wouldn't worry about a bit of black at the base of those) And you have a nice fat new root with growing green tip.

Phals don't mind being repotted in spike or even in bloom, and I think that is what you should consider for this one. Take it out of the pot, you can clip off the old rotted part of the stem that has no roots or leaves. Then gently coax those new roots into the pot (you can twist the plant as you put it back, so that the good roots follow the inside surface of the pot) and down into it, add fresh medium (I suggest medium bark). Remember, with fresh medium, it will need more frequent watering because the new bark won't hold as much moisture. That is a good thing, Phals want "humid air" rather than "wet".

[pottedlavalamp]

Hi Roberta,
Thank you for your response. I'm relieved to hear there is some hope.

I'll cut off the old stem and repot. Could you advise at what point to cut the stem? My instinct is to cut it just below the healthy section to minimise trauma.

Also, is there any treatment I should apply to the cut to to prevent disease, or is it enough to just keep an eye on it?

Thank you!

[Roberta]

You're correct... cut the bad part that is rootless. In fact you may just be able to snap off that part - it likely is dry and brittle. Then you won't risk cutting into healthy tissue. If you do cut it and find that you cut a little too high (and got fresh green stem) you can dab a little cinnamon on the cut. (It's a natural fungicide..., just keep it off the roots) Or, simply let it dry for a day or two before you add medium back into the pot.

[estación seca]

Welcome!

Phals grow slowly but continuously upward. The old stem dies back eventually. As you grow orchids you'll see this again.

[pottedlavalamp]

Roberta,
I have repotted my phal in bark and cut off the old dead stem. I have attached some photos for you. I just put a little bit of sphagnum moss over the holes in the pot to stop the bark from falling out. I didn't mix it through like last time. The roots were not nearly as rotted as I feared.

Thank you for your help, I appreciate your generosity.

[Roberta]

You're welcome. It already looks happier. (Freshly-potted orchids usually do...) Do remember that you'll need to water more often with the fresh bark. One way to get a feel for how often: Water well, let drain, then weigh on a postal scale or kitchen scale. Weigh the next day, etc. When the rate of weight loss slows down (not much more water to evaporate) it's time to water again. After you do this a few times, you'll have a feel for how often it is needed.

[pottedlavalamp]

Hi Estación,
This is my oldest orchid by far. Mostly I get given unhappy orchids by my family to bring back to life and then return. I only have a couple of my own. I haven't had one in my custody for enough time for old roots to decay like these ones have. It never occured to me that age was a factor! A nice problem to have for a change.
Here's hoping I have more old orchids in my future

---------- Post added at 10:41 AM ---------- Previous post was at 10:34 AM ----------

That is an excellent tip, thank you. I'll go weigh her now. I was a bit weary changing the medium I use because I had a good sense of how my usual mix behaved. Having a method will be reassuring. The pot is far heavier with all bark chip, I used to know when she was ready for a drink by feel.