Masdevallia potting mix
 

Hey there,

I got my Masdevallia paivaeana a week ago and since then I've noticed that the potting mix is getting mold.

I've tried to change its potting mix(Mix of Bark and Coco chips), but it keeps coming back.

What can I do ? What is wrong?

It could be that it needs more air circulation. Usually molds appear when the air is stagnant and the medium is soaking wet.

Jan

I agree with the air circulation. The medium appears to be in good shape and is not old. Are you growing this out in the open, or in a terrarium? What are your temperatures?

you cannot afford to speculate, you need to investigate.

That means repotting.

The mold is confined to where the rootball is. This would suggest there is a high likelihood there is a propagating plug or whatever they are called hidden in the rootball.

That needs to come out. I agree the main media does not look degraded but once it has been infected with mold spores it is best to discard it.

Give the roots a good rinse under the tap and remove any old media that has mold spores. Remove any old squeezable roots that are no longer functioning. You feel the roots for firmness to do this. Any dead roots left behind can respread the mold so remove as much dead material and all the old stuff, give it a good rinse and that will solve the proble, you will not need any harsh chemicals to sort this out.

But if you don't do it properly it will just keep coming back.

The OP indicated that they had repotted... Masdevallias do grow on the damp side, and this particular species comes from a range of elevations so likely is not particularly temperature-sensitive. But while wet, they do need air circulation. I use fairly loose sphagnum (moisture-retentive but airy), in clay pots (evaporative cooling of roots) but certainly there are lots of other combinations that accomplish the same thing. We need more information from the OP about the growing environment, I think, to further advise.

ah ok then old roots were not removed properly.

just my 2 cents on the matter.

Highly unlikely to be too humid stagnant conditions but that of course also promotes mold, circulating air with a fan and lowering humidity will help if that is the cause