Snow mold in orchid media
 

Hello!

I need advice with snow mold in my media. I noticed it growing inside one of my phal pots. It was about to bloom so I held off on repotting it which caused it to spread onto the roots. I recently did repot it into fresh media (bark and sphagnum moss mix). I didn't do anything to treat it per say but I dont see it on the roots anymore. I am assuming it got washed off when I was repotting.

I've now noticed a couple of my other phals have some snow mold growing on the bark deep in the pot. I am planning on repotting but wondering should I be treating the roots with anything prior to putting it in it's new pot with fresh media? Would something like hydrogen peroxide be a good choice? And is there anything I need to watch out for when using it? As in, is it harmful to roots or to the plant?

Thanks!

H2O2 applied on the roots will probably kill them.
Fresh medium, good air flow.

Thank you! Can I just soak it straight into the hydrogen peroxide or how do you reccomend I apply it?

What rbarata said was the peroxide on the roots will kill them - meaning the roots! So don't do it! Fresh medium will take care of the mold issue - just rinse off the roots before repotting. The mold isn't hurting anything itself, just a sign that you have bad conditions down there - which repotting will take care of.

Not to derail, but I have what looks like a white fungus growing in my media. The orchid is growing fine and seems unaffected; should I be worried though? Do I need to repot?

https://i.imgur.com/i7LU4Tk.jpg

You don't want to wait until the orchid is in distress to repot. The mold isn't likely to hurt the plant, but bad medium eventually will (and the mold could be an indicator of that). The medium looks really well drained, but underneath, is it staying too wet? How long ago was it repotted? And which orchid? It may be that you can control it just by cutting back on the water somewhat and/or improving air flow with a fan. If the plant is one that wants to dry out somewhat (like a Catt) then you may just need to reduce water. If it is a Pleurothallid that wants to stay wet, then repotting might be in your future.

The best course of action when dealing with these sort of molds is to repot. They generally don't harm living root tissue and are growing on bark because it's pretty badly degraded. The mold itself is not a problem, but is a good indicator that you have a more serious problem: a medium which has long exceeded it's useful lifespan and which creates a stale a soggy root environment.

In general, it's wise to avoid spraying anything on the roots since it's rather sensitive plant tissue. Sometimes if I see iffy things on the roots I'll just wait a day between unpotting and repotting and let the plant sit bareroot to dry out