Mould on Media

[hchan]

My new seedlings seem to be doing well so far; the leaves look healthy and there has been new leaf growth. However, overnight I've noticed that some of them have mould growing on the surface of the media. One particular seedling seems to be affected the most and has mould throughout the media not just on the surface, probably the one that started the problem. I've quarantined the bad ones and will repot them in new media ASAP. In fact I'll probably repot them all just in case. I haven't decided yet whether to use hydrogen peroxide or cinnamon to clean them during repotting any suggestions please? I'd prefer not to use a strong commercial anti-fungal if possible.

Is this a sign of too much humidity, too warm (heatwaves for the last week), not enough air flow or maybe a combination of these factors?

 

[Paphman910]

I would increase air flow to reduce mold growth. Your medium holds water so mold will grow on it. I had this happen on coconut husk medium. What I did was let the medium dry out on top and it seemed to help.

Paphman910

 

[SlipperFan]

Is it mold or algae?

 

[hchan]

Is it mold or algae?

Definitely mould I think, it's grey/white and filamentous. Just a bit more info. It's inside a terrarium setup so does get very humid. I do have a fan going, but possibly that it's not enough. I do take the cover off it overnight so it doesn't get cold and humid, then I replace the cover in the morning and turn the fan back on.

 

[SlipperFan]

Sounds like mold. Could you leave the fan on all the time? First, though, you need to get rid of the mold. Can you pick it off and then spray with Physan or another anti-fungal?

 

[hchan]

The fan I have at the moment is just temporary one and I can't leave it on all the time, but I'm going to order a better one that I can leave on.

I'm not sure that I can pick it off, but I will try. I'm assuming that on the badly affected one it must be on the roots, but possibly the other ones won't have it on the roots just yet. Physan is not available here in Australia and I don't want to use something like Triforine inside the house. I've just bought some hydrogen peroxide (3% solution) and plan to soak the roots in the solution before repotting. Any ideas how long I should soak for? Would soaking in 1.5% solution for 5 minutes be enough?

 

[hchan]

Ok it's done, all repotted now into S/H. I did in the end soak in 1.5% hydrogen peroxide for 4-5 minutes.

Actually patient zero had lovely root growth happening, go figure. Still glad I repotted everything though as the probability that it was some fabulous mycorrhizal fungus was pretty low. BTW, one of the Berenice seedlings already has a second growth developing, seems a bit premature...

 

[SlipperFan]

Good luck, Hubert. It sounds like you made the right choice with the hydrogen peroxide soak. I'm curious, why did you decide to repot in S/H?

 

[hchan]

Thanks Dot It was always my plan to repot them into S/H eventually. However, since I'm new to paphs, I wanted to make sure some of my other culture variables were more or less right before changing to S/H. I repotted two of the seedlings immediately into S/H on receiving them and was going to wait a while longer before doing the others. The first two seem to be doing fine so far.

S/H tends to work better for me as I tend to travel for work and when I'm not traveling I have a tendency to overwater. In fact I'm just about to fly to Switzerland for a week, in just a couple of hours...

 

[SlipperFan]

Safe trip!

 

[emydura]

I know the fungus you mean. I had the same problem in my fish tank. I also currently have the same problem in my glasshouse. It seems a real problem with CHC's but some of my pots with bark also has it. I have pretty good air movement in the glasshouse as well. The fungus can really keep the mix dry - making it a bit water repellant.

David