Mold on Seedling grow medium - Page 2

SharonRossy · April 3, 2014

Once I took off the domes removed the mold and let the soil dry out a bit, it seems to have stopped. So hopefully, no harm done.

bower · April 3, 2014

I think we're talking about two different things here. The mold that worries me is fluffy white stuff that collapses on contact with water. Luigiwu your picture looks more like a crustose lichen than the mold I was talking about. Or am I mistaken?

I also commonly see these lichens on the surface of potting soil after weeks, not days, of the soil surface being undisturbed. They are impervious to being watered as they are to drying out, and are not affected by air circulation like the fluffy stuff that likes to bloom where it's enclosed and still. Afaik they are completely harmless to the plants. They can be disrupted by ruffling the soil surface with your finger, or picked off, since they do not have hyphae extending into the soil as a mold will more likely do.

If it's really a mold in your bucket - a soft white growth not a hard lichen - I wouldn't personally use that for starting seeds. If it's the surface of a large volume I would remove and discard the top inch or so, and use the rest for some other purpose - outdoors even. If it's a small volume in the bucket, maybe use it to test for efficacy of other treatments - like the Serenade for example. And report your findings, of course! No bit of mold is worthless, as knowledge is priceless!

Ask Alexander Fleming.

luigiwu · April 3, 2014

Hey there. This is all very new to me so you might be right. I had to google "crustose lichen" and some of the picture are pretty extreme - mine just looks like an extremely light dusting of say, baby powder or powder sugar. But you're right - my white stuff is not "poofy" or "fluffy." Its simply white and I just assume it was mold. I sprayed Hydrogen Peroxide on it and it did nothing. The kale seedlings don't look too good now though - I wonder if its from the hydrogen peroxide... Meanwhile my tomato plants are super hardy and going strong (knock on wood!)

April 3, 2014	#16
SharonRossy Tomatovillian™ Join Date: Jul 2012 Location: Montreal Posts: 1,140	Once I took off the domes removed the mold and let the soil dry out a bit, it seems to have stopped. So hopefully, no harm done.

April 3, 2014	#17
bower Tomatovillian™ Join Date: Feb 2012 Location: Newfoundland, Canada Posts: 6,794	I think we're talking about two different things here. The mold that worries me is fluffy white stuff that collapses on contact with water. Luigiwu your picture looks more like a crustose lichen than the mold I was talking about. Or am I mistaken? I also commonly see these lichens on the surface of potting soil after weeks, not days, of the soil surface being undisturbed. They are impervious to being watered as they are to drying out, and are not affected by air circulation like the fluffy stuff that likes to bloom where it's enclosed and still. Afaik they are completely harmless to the plants. They can be disrupted by ruffling the soil surface with your finger, or picked off, since they do not have hyphae extending into the soil as a mold will more likely do. If it's really a mold in your bucket - a soft white growth not a hard lichen - I wouldn't personally use that for starting seeds. If it's the surface of a large volume I would remove and discard the top inch or so, and use the rest for some other purpose - outdoors even. If it's a small volume in the bucket, maybe use it to test for efficacy of other treatments - like the Serenade for example. And report your findings, of course! No bit of mold is worthless, as knowledge is priceless! Ask Alexander Fleming.

April 3, 2014	#18
luigiwu Tomatovillian™ Join Date: Jun 2013 Location: ny Posts: 1,219	Hey there. This is all very new to me so you might be right. I had to google "crustose lichen" and some of the picture are pretty extreme - mine just looks like an extremely light dusting of say, baby powder or powder sugar. But you're right - my white stuff is not "poofy" or "fluffy." Its simply white and I just assume it was mold. I sprayed Hydrogen Peroxide on it and it did nothing. The kale seedlings don't look too good now though - I wonder if its from the hydrogen peroxide... Meanwhile my tomato plants are super hardy and going strong (knock on wood!)