Mold, mold mold! It keeps reappearing! I'm not panicking… yet!

[donguri]

Hi everyone!

I’m quite new here. My history of orchids goes back a mere one year, as of yet. My orchid roommates – those involved – and I have successfully combatted black root rot, a slight infestation of meelybugs, mmm, what else? Not much really, a moving to a brighter location maybe, but that actually was an improvement. Things have been going pretty smooth so far.

…But now… I bought two lovely red jewels, namely Burrageara Nelly Isler and Horweara Lava Burst through a website, and one tiny Phalaenopsis in a flower shop. I inspected them more thoroughly when I got them home and in all 3 cases I identified fuzzy white-gray mold between the roots just below the surface. When I say mold, I mean those really small white-gray hairlike cobwebby formations that smell like mold (that’s the kind of wet cellar smell – this gives me some ideas: Wet cellar = wet, cold, dark, no aeration. This is what I have to solve.)

I decided to repot them, and needless to say, directly around the crown base they were all tightly packed in old sphagnum moss below the surface layer of bark – except for the teeny-tiny one, which had only the moss media, quite nasty, in a very very small pot. Although finding old moss and hence some squishy roots in the middle is not unusual with newly bought orchids, the strong precene of mold was really alarming. I disinfected them with hydrogen-peroxide, repotted them into more spacious media (mainly fresh bark, just a speck of fresh sphagnum here and there), punched ventilation holes in the sides of their pots. Could have been the end of story, everyone lived happily ever after, yaddayadda. Except it wasn’t so.

I have had them for 3 weeks now and the friggin’ mold just keeps reappearing. I did not want to repot and disturb them again so soon (although I’m beginning to consider it), so I poured some hydrogen-peroxide (as if watering) on the roots through the media, then I got some cinnamon oil and (diluted in water about 1% oil, 99% water, more or less). The mold was gone … for a few days.
How does it keep reappearing !?!
My room temperature may have something to do with it. In these past weeks it has been mostly around or slightly (=1-2°) below 20° Celsius. Not very high. This could be one of the factors.

The orchids are thriving, but they are struggling, their bulbs (resembling oncidiums’) are wrinkly (will wrinkled bulbs ever un-wrinkle again if healthy? I bought them wrinkly.) The mold keeps reappearing, and I can see the plants are suffering. For one, one of them (the Burrageara Nelly Isler) dropped all its flowers, although the mold is less obvious – but it had fewer roots. The other one, which seemed to have a more extensive root system (the Horweara Lava Burst) looks okay, still has its flowers on, but the mold! it’s more obvious (and smellbvious). The phal, well that one is a little older – about a month – with hardly any roots left. Has a one flower stalk that I kept as a balancing aid, because the remaining roots wouldn’t be able to keep it upright. It strives, but there’s no developement, (okay, one month can be a short time, but) its leaves are slooowly getting more and more wrinkly. This one has been repotted twice (bark), had taken a hydrogen-peroxide root bath, and a dry spell for almost 3-4 days now. It doesn’t look good. I can’t see to the roots, what few are left of them. I’ll water it today. Alternatively, I’m thinking about mounting this one on a corkwood block with some sphagnum to grow new roots. It would dry out a lot faster, but would have to get on a more frequent watering schedule as well (daily instead of weekly). Do you think that’s a good idea? Drying out would discourage mold growth and I could also freely inspect the roots, but would it work for this Phalaenopsis?

How will I get rid of the mold without accidentally getting rid of these tender orchids?
It is quite possible I’m doing something wrong, or the mould wouldn’t reappear all the time. Or maybe it needs several treatments. Should I disturb the orchids to expose the roots again to see the damage and repot?

Let’s see what more specifics could be involved:

Orchids involved: Burrageara Nelly Isler, Horweara Lava Burst, Mini Phalaenopsis hybrid.

Room temperature: mostly 18-24°C

Humidity tray: Yes, each. This in fact could be a bad idea as mold likes humidity…

Aeration: Roof window’s slightly open all day. Good air movement at that spot, actually in the rest of the room too. They are close to the window, but this could also mean slightly lower temperatures…

Light: reasonably good. Below South-Western roof window, longest period of light per day, not directly, but in slight shade, no sunspots, but rather reflected light … okay, that’s less heat. Lighting may be a bit inadequate then. However, they did worse in the other (North-Western) bigger window, where air movement was less (because of difficulty opening that window: if I open it, it lets in too much air (windy) = draft).

Watering: I usually water my orchids once a week, but check on them every day before and after work, or at least every day once. Most of the caring is done on a weekend day. Watering is administered two ways: by careful soaking of the media in the pot for a while, with no water reaching the crown, or alternately, from above, in the sink, generously, but also very carefully about the crown. Depends on how dry the medium is – soaking is more efficient, but leaves the media wet for a longer period.

Attention given: I check them frequently and try to take good, gentle care of them. Hopefully.

Other orchids: all doing very well so far. Temperature and general conditions are just about the same as for the moldy ones, yet no damage. They’re lovely, new leaf and root growth, no appearant problems. Lots of joy.

Thank you so much for reading this loooong case report.

If you have the time, kindness and experience, please leave me a few suggestions.

How does mold reappear if the roots been disinfected? Maybe I did it improperly? I watered them right after repotting. Should I not have done that? They looked thirsty, but maybe their roots just were exhausted and water did not help like that. Should I remove them from their humidity tray for a while? (Tray: pot rests on clay pellets, water amidst the clay pellets does not reach the roots.) I can only raise day temperature if I close the window, which means less air movement, but still some. Should I change that? What can I do to provide them the right conditions to battle this mold? Do Nelly Isler and Lava Burst need different kind of care than what I’ve been giving them? Oh how do I get rid of the mold problem?

Thank you for your kind attention!

donguri

[Daethen]

My first concern is the cinnamon oil. Did you pour this over the roots and media? It will dry the roots up if you did. How long did you soak the root systems in the peroxide solution? Maybe a longer soak? I am no true expert but am going on 4 years of growing. Seem to finally be getting some continued good results. Experts will be along shortly.

[donguri]

Oh no! I poured it over the media, about 2-3 millilitres, a 1 pecent solution in water and about 1 percent of sensitive dishwasher detergent (baby stuff) for the oil to mix well. I dared use it because it is supposed to be an effective pesti/fungicide. This is the first time I used it in oil form. I've used cinnamon before in powder form, for cuts and black fungal spots on root, with success. But here there was no wound, and I did not want to cover the whole root system in powder. Since the oiling, I already watered the orchids in the sink once, so I guess the roots got a thorough washing under running water.

The hydrogen-peroxide (3%) bath was only for the phalaenopsis and it lasted about a minute or so, because on inspection I detected a white fungal area (about a few millimetres white) at the base of the roots, like a flattened cotton swab, and because peroxide spraying simply didn't seem to get rid of the mold in the long run.

Thank you for your reply.

---------- Post added at 08:38 PM ---------- Previous post was at 08:35 PM ----------

Also, about cinnamon oil, by 2-3 millilitres poured over the media to trickle to the roots (around the base) I mean 2-3, max. 4 millis of the 1% solution.

[silken]

I'm not an expert either but have been growing for a few years. Never put cinnamon in any form on roots! As Daethen says, it will dry them up. Hopefully they have been thoroughly flushed since. The cinnamon makes a great disinfectant for cuts and problems on the plant leaves and bulbs but not roots.

I've never had a mold problem but mold does grow in damp places usually. Everything sounds good as far as an open bark medium, holes in pots and your temps sound fine. The only thing I can think is since some mold spores were present on roots, that they re-asserted themselves in your new media. I would likely have used a rinse on all the roots such as the hydrogen peroxide, Listerine or some Physan if you can get that there. Then sterilize pot and media. I like to put my bark in a Pyrex bowl and boil it in some water in the microwave for a few mins. Whether there is any benefit, I don't really know, but at least it is somewhat sterilized. You did say you have some vents open, but a small fan moving air 24/7 would help too.

[Orchid Whisperer]

donguri, I would quickly remove all growing medium from the plant that you did this to, discard the medium, and thoroughly rinse what is left of the roots. Re-pot in fresh growing medium. Water your plants less often, and hopefully the mold will not return.

Dishwasher detergent typically contains bleach - a powerful oxidant. This will kill roots. The cinnamon oil will also kill roots.

I have used the dilute cinnamon extract-dish detergent solution to clean leaves and kill insects on leaves. The detergent to use is the type used to clean dishes in the sink, not a dishwasher machine (I think in the UK they call this washing-up liquid; not sure about in your country).

The home-made remedies can be useful, but if they are not formulated with the right ingredients and at the right concentrations, or if they are used incorrectly, they can kill your plants.

[donguri]

I decided to inspect the roots of each tomorrow and see if I left any dead roots there, just to be on the safe side.

This is the first time I encountered mold with orchids. Some articles say there is a mold that's harmless and simply feeds on dead tissue, but leaves live tissue alone. If this is that kind on the Oncydium-like ones, should it be there below surface, smelling like a moldy cellar?

Also with the phal, at first (when I bought it home) there were many roots, many of them squishy. I cut away all those. H2O2 spraying roots generously. Repotted. Inspected again, even more decaying roots were found. Moldy smell. Happened fast. Hard roots became squishy. Cut away those too, hardly any left. H2O2 bath for the roots. Repotted. Now anxiously waiting. Leaves are getting wrinkly. But maybe because so few little roots are left? Ah, there are so many possibilities, reasonings. I think I will mount this one on corkwood. At least then I'll be able to see what's going on.

Getting experience is a great thing, but the poor things, they suffer my ignorance. As well as bad past conditions - the mold came with them when I got them. I guess I'll just do what I can and put some faith in them. Grow! Grow! Grow!!

---------- Post added at 09:41 PM ---------- Previous post was at 09:37 PM ----------

Orchid Whisperer, thank you for your reply. I just noticed the replies came in while I was busy typing. I will repot them and wash them thoroughly. So cinnamon oil on roots was a pretty bad idea afterall...

Okay, next phase, washing, disinfecting, repotting. And hoping.

---------- Post added at 09:46 PM ---------- Previous post was at 09:41 PM ----------

Also, Silken, thank you!

I'll update when there's progress, in the meanwhile, I'll keep reading replies and learning about this.

[Daethen]

Believe it or not, you are probably better off with too dry over too wet when there are few roots. Without adequate roots the plant can't take up the water. When the media is dryish the plant tends to put out more roots searching for water. I had one plant that I waited too long to change media on and it smelled like old mushrooms. I removed all old media, did a longish peroxide soak after removing all bad roots and repotted in a new pot with new presoaked media. Then wait until it is pretty much dry before watering. Once you start to get new roots, you can then start to water a bit more often. A fan is a great tool for air movement without lowering temps.

[donguri]

Thank you Daethen! I'm repotting them tonight, actually in a few minutes. Thank you also for your advice on how to proceed from there. Hopefully I can maintain this wet-dry balance.

Now comes the patience part, which is exciting but frustrating at the same time - there can be so much time before I can see whether I'm doing it right, plus one wrong move and...

Well, time to see what gives : )

[Daethen]

Good luck and keep us posted on how it is going.

[Atzau]

I had this problem with one of my mini phals. I did the same thing with the peroxide rinse. Found that it really dessicated my roots. Don't know if it was the peroxide or what. Anyways, i changed it to bark media (it was in Moss when i got it) and kept it very dry. The leaves that were there had gotten limp and wrinkly but it has since bounced back with 2 new firm leaves and the start of several new plump green roots. I think the key is to keep it fairly dry. Mines that way just due to supervised neglect. Lol