Green/white mold on phalaenopsis roots

[Phalaenoptics]

Hi all! Thank you for your replies. They were very informative and helpful!

My diagnostic, now that I have some more experience and knowledge under my belt:

My environment is wildly variable. For example, just this summer we'll have a week of 100+ degree weather (39-40C) with high humidity followed by days in the 60's. When it's cold and wet is when mold happens. When the weather is hot and the media dries out, the mold goes away. like ES mentioned, it does not grow on live tissue, but if some parts of the velamen on a live root has a black spot, it may grow on that. I now have most of my phals potted in very airy mixes, save for one experiment that's very happy in full sphagnum moss. I am in the process of figuring out the balance between maintaining humid atmosphere plus airflow but also not so much air that the roots dry out when the humidity drops.

The only way I can deal with this is to keep an eye on the weather report and adjust my watering accordingly.

Up until the point I had experienced mold for the first time, I'd only had my phals in beautiful pristine conditions. So when I saw the mold on everything with that one plant, I freaked out and proceeded to overcorrect. You guys may be right that the "just add ice" orchid already came with some fungal issues although it appeared healthy with many green roots at the start.

Edit: Now that I think about it, it did have a mildew smell when I watered, so the bark medium was very broken down.

(The unidentified bug I saw was possibly some kind of soil mite. I have seen it again on one of my other phals, and it's actually the biggest and healthiest one. The mites don't hang out on the leaves or stem and stay down in the media unless I water.)

The biggest lesson I have learned from my mistakes is to let the plants acclimate to my rough home environment and let well enough alone! In the last few weeks I've seen roots that have black sections grow green living root tips. I have had roots die off in the pot, and I can see some mold growth where they died in the pot, but it's surrounded by bright green roots that are doing well, and the orchid as a whole is doing well. So I no longer unpot at the slightest sign of imperfection and mess with it.

Unpotting it, cutting things off, spraying with hydrogen peroxide, has only stressed out the orchids and contributed to their decline. (Except for that initial repot from the store, of course!)

Sadly, no matter how much theoretical knowledge one has, this can only be learned from experience, especially with my difficult environs. I also strive to learn from others' posts and experiences, so thank you all for your knowledge!

[mvmgems]

Hey Phalaenoptics, by any chance are you using recently-purchased Repotme Monterey bark mix?

I just found this thread on r/orchids from a couple of days ago with several other people with the same issue. The mix I use is predominantly Repotme Monterey bark Imperial mix that I bought 4-6 weeks ago.

Edit for grammar.

[Shadeflower]

I still think as orchid growers we should be aware of what makes the pests that affect our orchids thrive. Whether mold affects an orchid, I should think it wouldn't be ideal and would certainly break the bark down faster at the least. In an orchid pot it will always be over 60% humidity. If it isn't then the orchid will suffer.
Dismissing that fact is not really helpful. Like pointed out air movement is the best way to prevent stale build ups of humidity. Mold multiplies in humid conditions. We cannot stop our pots being humid, most of mine go over 90% at night. I've stuck a humidity probe into the pots. Thats when the orchids seem to get hydrated most.
If you have mold spores multiplying in your home it can quickly become a problem. Just like mites left unchecked will quickly become a problem.

I know too well about mold, I live in the UK... Luckily I haven't got mold anymore but council houses here are built with the cheapest building materials that are prone to leak and accumulate damp, these are ideal growing conditions for mold. The less mold can multiply the less it occurs.

Mold in House on Walls, Ceiling, Windows, How to Remove, Causes

[Phalaenoptics]

Originally Posted by mvmgems

Hey Phalaenoptics, by any chance are you using recently-purchased Repotme Monterey bark mix?

I just found this thread on r/orchids from a couple of days ago with several other people with the same issue. The mix I use is predominantly Repotme Monterey bark Imperial mix that I bought 4-6 weeks ago.

Edit for grammar.

I did have a Repotme orchid mix ( classic phalaenopsis mix) but it's actually performed really well for me. My mold issues started when I used a different bark medium from Amazon because I wanted to try customizing my own mix. 😔 I added in perlite and a little sphagnum moss, but it was mostly chunky bark.

The bark didn't look broken down when I first inspected it. It did seem to break down quickly after I boiled it for an hour to prepare it for use. It would be easy for me to blame the mix entirely, but I definitely think my environment played a factor ( from learning and reading other's posts) since it has been quite cold and rainy this summer!

---------- Post added at 03:12 PM ---------- Previous post was at 02:18 PM ----------

Originally Posted by Shadeflower

I still think as orchid growers we should be aware of what makes the pests that affect our orchids thrive. Whether mold affects an orchid, I should think it wouldn't be ideal and would certainly break the bark down faster at the least. In an orchid pot it will always be over 60% humidity. If it isn't then the orchid will suffer.
Dismissing that fact is not really helpful. Like pointed out air movement is the best way to prevent stale build ups of humidity. Mold multiplies in humid conditions. We cannot stop our pots being humid, most of mine go over 90% at night. I've stuck a humidity probe into the pots. Thats when the orchids seem to get hydrated most.
If you have mold spores multiplying in your home it can quickly become a problem. Just like mites left unchecked will quickly become a problem.

I know too well about mold, I live in the UK... Luckily I haven't got mold anymore but council houses here are built with the cheapest building materials that are prone to leak and accumulate damp, these are ideal growing conditions for mold. The less mold can multiply the less it occurs.

Mold in House on Walls, Ceiling, Windows, How to Remove, Causes

@Shadeflower after reading your post I went and gave it some thought. Since you live in the UK, I think you also understand what it's like to live in a variable climate. ( I'm in New England, by the sea. Very hot summers, very cold winters) I would of course prefer to grow beautiful pristine plants as much as possible! My home environment actually tends towards dryness, but the orchid pots are kept very humid so that the plants can grow big and happy. It's just been an incredibly wet summer with heat waves interspersed by temperature drops and thunderstorms.

So I wanted to give an update!

Miniphal #1: had some of that spider-web like white mold on 2 roots. 🤢 I was trying to leave it alone, but it did bother me. It had finished blooming, so I unpotted it to find one decaying black root that was connected to a green bit. Removed the decaying velamen, washed off the roots, sprayed some physan 20, repotted in fresh medium with the stem much higher up. Growth of new leaf paused for a little bit but it seems to have resumed!

Miniphal #2: this one had been struggling a little since it had come potted with another mini and it was overpotted, the medium never drying out. It's in rehab. Root system didn't look great, only a few firm roots left, most of them sad-looking. Probably has one good green root. Since it doesn't have many roots left I didn't want to cut any. Repotted in much smaller pot with coco chips, leca, and some sphagnum. I'm going to baby it until it starts recovery. Leaves have been perking up and dewrinkling. Occasionally it does get a little bit of white fuzz on an exposed root, but I've been spot-treating with physan 20 and it takes care of the issue.

( Someone tell me if it's not safe to spot treat with physan 20.)

My favorite phalaenopsis: has one or two pieces of coco husk with white mold growing on the media deep in the pot. It's in a mix with lots of airspaces and airflow. I opted to leave it alone since it's on its second rebloom of the year, pushing out new roots, and working on its 9th leaf!! I also decided to add some dish soap every few waterings to keep the soil mite population down. I haven't seen very many of them since.

So, I'm still tweaking my care and learning to deal with my challenging environment. But I really appreciate everyone's feedback and experience - it always gives me something new to think about!