Mold in pot?

[gabbro]

Hello, I'm new to keeping orchids, I received a phalaenopsis about one year ago as a gift. Recently I decided to repot it, and soon after I started noticing mold inside the medium. I don't mean white mold on the roots which seems to be a common problem, I mean green mold growing on the bark inside the pot. I've also seen a few previously healthy roots soon start to rot. I tried to add more holes in the pot for more ventilation but the mold keeps coming back. I suspect it may be a problem of the medium, because it was given to me by my aunt who had orchids in the past but it's quite old, and the problem also never presented itself before I repotted.
Can anyone give me advice on how to handle this? I'm looking to buy new bark to put in place of the moldy one, but I don't know how to treat the orchid in case the mold got on the roots too. I'm just very confused as to why it's happening, because I'm watering it as often as I did before and it seemed to be alright back then.

[Roberta]

First, Welcome!

The green stuff is algae - it is harmless. However, I suspect that the medium is bad, and so staying much too wet. Repotting with that new bark is the solution to the problem. There is no special treatment needed - just take it out of the pot, and wash the roots under the faucet . If there is mushy black rotted stuff (the velamin, outer coating of the roots) you can pull it off easily with your fingers. If the center "string" of the bad root is still firmly attached, leave it - it can still help the plant if there are few good roots. After you take it out of the pot, if you can post a picture it will be possible to advise much better. Otherwise, I'm just guessing.

To post a photo, click the Go Advanced button, and a bit down the screen is Manage Attachments. That will give you a pop-up to attach photos. Click Upload. Some have noted that one needs to have 5 posts to upload photos, but I have seen some who have succeeded on the first or second post.

[gabbro]

Thank you for the advice! I still have to get the new bark - restrictions and all - but I'll try to do as you say once I have it

[camille1585]

Welcome to Orchidboard!!

If you don't mind paying shipping costs, you could have a look online for bark. For instance, at Nardotto e Capello or celaorchidee.it. Two nice vendors, and you could pick up a new orchid while you're at it.

It would still be good if you could share some photos with us, to make sure it's clear what the problem is!

I wouldn't worry about mold spreading to the roots, most are rather specific. The worry is more that the bark may be broken down and ends up suffocating the roots.

[estación seca]

Welcome to the Orchid Board!