Mold from Miracle Gro

13 years ago

I re-potted a few tomato seedlings last weekend from a bag of organic Miracle Gro. When I opened the bag there was a bit of mold (at least I think, it was white fuzzies) on the edges but as it was all I had at the time I used it anyways. Now there's white mold on the surface of the soil of the pots. Anyone else experience this? Should I re-pot them? (for the record, I don't like Miracle Gro's support of GMO research but it was the only organic soil available where I was)

Featured Answer

digdirt2

13 years ago

It is usually fungus, not molds, and these so-called "organic" mixes contain many different forms of fungus in the dehydrated chicken manure, feathers, etc. they add. The fungi usually only grow like this when provided with the ideal warm air temps and overly wet conditions.

So the solution when using these mixes is to reduce the ambient air temps, increase air circulation with a small fan of sorts, and cut back on the water. You can scrape it off the soil surface but it will just return unless the conditions that encourage it are eliminated.

Since those appear to be quite large pots for such small seedlings reducing the watering will have a double benefit.

For future reference any seed starting mix which does not contain added fertilizers (that the seedlings don't need anyway) is considered "organic" and approved for use by even certified organic growers. They contain only peat, coconut coir, and vermiculite or perlite. There are many of them available. Slapping the "Organic" label on as a few marketers do is just a marketing gimmick.

Dave

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Comments (7)

subtrop
13 years ago
And in addition to that I'd sprinkle cinnamon powder on the soil surface. It works as a natural fungi inhibitor.
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Solorya
Original Author
13 years ago
Thank you both. I do have a fan running in the room because I thought that might be the issue, but I will scrape it off and try the cinnamon as well.

And I'm going out of town for a bit and my mom will be watching the plants...I'm sort of betting on her to forget watering every couple of days :-) That's why they're in the larger pots now.
potterhead2
13 years ago
Please tell your Mom NOT to water "every couple of days"!!!
In those large pots it will probably take a week (at least) for the soil to dry out. You should only water tomatoes (and most plants) when the soil is pretty dry. poke your finger in a couple of inches. If you feel any moisture, do NOT water.
Brenda Maher
11 years ago
The soil I have is moldy in the bag. This is the second bag this year I have purchased with the same problem. Stupid me.
Seysonn_ 8a-NC/HZ-7
11 years ago
last modified: 11 years ago
I would only use soil less potting mix for start and seedlings. They are also organic but most without living organism in them. I even sanitize them with peroxide solution to prevent any fungal growth. Once potted and taken outside, it is another matter.

Sey
Labradors
11 years ago
I bought a huge bag of MG Organic one year and didn't read the back of the bag until I had filled all my large planters. It said "not for containers". Thinking that it might smell bad and THAT was the reason, I didn't panic and left my plants in that soil and they did poorly.

As Seysonn says above. It really is best to use soil-less potting mix for containers and especially to start seeds (because they can be prone to damping off disease). I learned the hard way!

Linda