Persistent white mold on Epidendrum roots

[Johnny-T]

Hello everyone, I am dealing with some type of mold on my Epidendrum floribundum (although now I think it was mislabeled by the seller and is a little different kind).

I got it like 3 month ago, it was potted in bark chips medium mixed with little bit of sphagnum moss and I just left it like that and put it on the east facing window. I watered it once a week, when the substrate was already becoming quite dry.

Then after a month or so, I saw some mold developing on the top of the substrate and later on the roots of the orchid. It looked something like this Google Image Result for https://i.stack.imgur.com/EiWB9.jpg. So I took the orchid out, cut some roots that seemed to be dead, used hydrogen peroxide to get rid of the mold on the roots and repotted it in brand new bark chips again mixed with little bit of sphagnum moss. It was looking good, one flower bloomed and other two buds were getting ready to bloom, when the mold struck again.

So I took it out again, repeated the same process, and ended up with the same result again. Now I took it out for the last time and killed the mold with hydrogen peroxide, but I think there must be something else wrong for the mold to develop over and over again. I have already cut most of the roots - they seem to be dying but not sure if because of root rot or maybe the peroxide. I didn't cut some of the dead roots completely, as seen in the photos, because they still are quite sturdy even though they seem dead or rotting (and because I would need to cut healthy roots to make space for cutting the dead ones completely). Other roots are quite dried up, since I am afraid if I watered them I would get the mold again. The photos below depict the orchid as it looks now.

Can you please give me advice on what I could do to save the orchid? I also though about getting rid of all the roots but I am a beginner grower and don't want to do anything too radical whithout an advice. Many thanks

[cooheyorchidman]

Hello! I am also a noobie. But, I was doing some perusing of the interwebs of what can help deter and somewhat destroy funguses and molds. I found that cinnamon is a great way to help combat and deter mold. Now an expert can chime in and possibly tell us of the dangers of using cinnamon in vast quantities and what the Orchid will use said cinnamon for when it is used in the orchid medium... But, specifically for the mold issue, I found cinnamon to be quite helpful as it has natural fungicidal properties. However, be wary as too much cinnamon may cause negative health impacts... the saying more is less is important. Here I will link where I am pulling all my information from and I find it imperative that you read it thoroughly so you do not harm yourself. I take no liability if you do and the responsibility of using this product property falls onto you!

Someone told me in regards to preventing mold growth that it is quite important to have a constant circulation of air wherever your medium is growing as this will make your orchid area unlikeable for mold spores to grow, it'll also help whatever water is in your medium evaporate quicker so that like I stated before mold'll possibly not have the chance to grow and spread. I wish you the best of luck and unfortunately, I do not have any sources pertaining to the perfect living conditions of mold.

Also, there is quite a lot of information on this forum pertaining to the usage of Hydrogen Peroxide and such on Orchids. The general consensus is don't use it. If you must do it sparingly and wipe it off after with plenty of water, as if any stay on the roots it'll burn them. Causing more potential stress.

Cinnamon as a Useful Preventive Substance for the Care of Human and Plant Health - PMC

[Roberta]

Originally Posted by Johnny-T

Hello everyone, I am dealing with some type of mold on my Epidendrum floribundum (although now I think it was mislabeled by the seller and is a little different kind).

I got it like 3 month ago, it was potted in bark chips medium mixed with little bit of sphagnum moss and I just left it like that and put it on the east facing window. I watered it once a week, when the substrate was already becoming quite dry.

Then after a month or so, I saw some mold developing on the top of the substrate and later on the roots of the orchid. It looked something like this Google Image Result for https://i.stack.imgur.com/EiWB9.jpg. So I took the orchid out, cut some roots that seemed to be dead, used hydrogen peroxide to get rid of the mold on the roots and repotted it in brand new bark chips again mixed with little bit of sphagnum moss. It was looking good, one flower bloomed and other two buds were getting ready to bloom, when the mold struck again.

So I took it out again, repeated the same process, and ended up with the same result again. Now I took it out for the last time and killed the mold with hydrogen peroxide, but I think there must be something else wrong for the mold to develop over and over again. I have already cut most of the roots - they seem to be dying but not sure if because of root rot or maybe the peroxide. I didn't cut some of the dead roots completely, as seen in the photos, because they still are quite sturdy even though they seem dead or rotting (and because I would need to cut healthy roots to make space for cutting the dead ones completely). Other roots are quite dried up, since I am afraid if I watered them I would get the mold again. The photos below depict the orchid as it looks now.

Can you please give me advice on what I could do to save the orchid? I also though about getting rid of all the roots but I am a beginner grower and don't want to do anything too radical whithout an advice. Many thanks

Stop cutting roots! The plant has no other way to get moisture! The roots are bad, and peroxide will make them worse. Cinnamon also damages roots. (new roots have little hairs, the peroxide destroys them) Those last few roots will at least help to hold the plant firmly in the medium while it grows new ones. (A soak in Kelpak, if you can obtain it, will help the rooting process) It is very important that the plant be held firmly in place - use a stake if you need to, since if it wobbles new roots may be damaged. (and stop taking it out of the pot!) You don't need sphagnum in the mix. Epidendrums don't need the extra moisture. What orchids need is good air circulation. A fan will help.

The mold is a symptom of poor cultural conditions. By itself, doesn't harm the plant, but it indicates conditions that are not good for the orchid. Likely, it is too wet and with not enough air movement.

[Ray]

I'm right there with Roberta on this one.

The majority of orchid ailments are begun with bad culture. "Medicines" won't help that.

[Johnny-T]

Ok, thanks for the responses, so I repotted the epidendrum (only bark chips), watered it and will try to provide better air circulation. But I am wondering, why is this orchid so prone to mold, it's not like the sphagnum moss was too moist for longer periods - after a week it was completely dry. None of the other orchids had problems with mold thankfully.

Just to be sure, what is a good watering schedule for epidendrums? Is it ok if it dries up and maybe stays dry for a few days?

[estación seca]

I don't see any mold on the photos you posted. I don't see any mold on the roots of the orchids in the link you posted. White fuzzy mold grows on dead plant material when temperatures are too low for many orchids, and humidity is high. You won't see it on living orchid roots.

I echo the advice never to cut off orchid roots. Orchids grow more slowly than most plants. You can't tell which roots are dead without a microscope. Removing roots sets the plants back. I think it's highly likely all the roots you cut off were healthy.

Going into the long, dark winter is not a good time to be repotting and injuring roots. Most species have seasonal growth patterns with not much happening in winter. The time to repot is just as roots begin, usually in Spring.

Reed-stem Epis. shouldn't dry out for long during the warm growing season. In winter, if they're not growing, it's OK to let them dry out for a few days. The watering interval will depend on ambient temperatures and relative humidity.

[Roberta]

Near-dryness, don't let it stay dry for a long, though. No idea why that one is getting mold while the others aren't. But remember, mold is a symptom... pretty harmless to the plant, more of an aesthetic issue. Fix the cultural problems and you'll fix the mold. My bigger concern about that particular plant is that it now lacks roots. Hopefully it will grow some new ones before it succumbs,

[Johnny-T]

I am sure there was mold on the roots and the last time, before I killed it, it was also growing on the lower part of the stems (halfway between roots and lowest leaf), so I was quite afraid it would damage the orchid. I found a picture with mold on orchid roots Google Image Result for http://www.orchidboard.com/community/attachment.php?attachmentid=82574&d=1369814255, although it really is hard to find one, too bad I didn't take a photo when the mold was still there.

Many of the roots I cut were definitely dead, as the were just dry empty shells (maybe because of peroxide?), but I guess I am guilty of unnecessarily cutting a few roots here and there . About the watering, the humidity is around 60% and temperature 18-22°C. I water the orchid by soaking it in water for a few minutes and after watering it yesterday, I see that the top of the substrate is dry already and the roots do not go very deep, so it might be time to water again soon

[estación seca]

The water conducting part of the root, with living vascular tissue, is the thin thread down the center. It is surrounded by velamen, spongelike water conducting remnants of cells. Velamen starts out white and turns brown. Brown velamen that strips off the central core is not an indicator of dead roots. Those cores may still take up water. Many orchids with strongly seasonal growth patterns have tan, dry looking roots by winter. These are not dead.