Mold when starting seeds?

Ruby · March 21, 2007

I started some seeds (Craig's method) and after about 4 days I have some greenish mold growing on top of the mix (just a tiny bit in one cell). It's not dark green, but sort of greyish green with a little bit of white fluffy looking stuff (again, not that much but in more than one cell).

This happened a couple weeks ago in a deeper flat of seed and I watered with a diluted hydrogen peroxide mixture to make myself feel better, but I wanted to find out maybe what I should actually be doing in this case.

I don't know if it's just something in the air (yesterday and today have been cold and rainy). I'm pretty sure it's some combination of air temperature/moisture and possibly contaminated seed.

Anyhow, I'm not too concerned, but I'd like to know the best way to treat this at the point I'm at now without throwing out the tray. I've taken off the plastic wrap (it was loose, for air circulation) because some seedlings are popping up. Seaweed extract? Hydrogen peroxide? Baking soda? Cinnamon?

I thought it was a fluke the first time it happened, but it happened again so I thought I'd ask. Perhaps others have had the same issue.

spyfferoni · March 21, 2007

I've heard watering with chamomile tea is helpful for mold and crud. I'm sure others will say something about it. I haven't had to use it yet.

Tyff

Ruby · March 21, 2007

First batch was miracle grow seed starting mix and the second one was pro-mix.

**carolyn137** · March 21, 2007

Ruby PMed me about this b'c I had sent her three tomato varieties and she told me that the mold was growing where the one variety was planted which suggested to her that the seed for that variety were contaminated with fungi, but not the other varieties I sent.

So I'm glad to come here to see it was on top of the mix, as I assumed.

While it's true that seeds can have adventitious fungal spores attached, and some may not be removed by Fermentation, those spores are NOT from fungi that make visible colored growth in mixes such as is being described.

And spores for the genera and species that can cause damping off are in the mix, not seedborne.

Ruby, you're describing the vegetative forms of normal airborne transmitted fungi, not pathogenic fungi.

They aren't a problem so just scrape off those areas and continue on. Had you been using peat pots, for instance, you would have seen sometimes the whole outside turn green with mold as well as the surface of the mix.

No need to treat such areas with peroxide, which doesn't work anyway, or with chamomile tea, the latter of which has been suggested to be used to prevent damping off.

Remember that there's both pre and post emergent damping off and you don't even see the fungal growth when you see the first seedlings fall over with damping off but then may see the fine white filaments later.

So I'm here to post b'c Ruby told me about her thread, and I'm here to hopefully clear up any confusion with normal environmental fungi vs pathogenic fungi adhering to seed surfaces.

As I also told Ruby, the variety in question that I had sent her that had mold growing in the area has been grown from the same seeds by several hundred folks with no problems at all. And the two other varieties I sent her were processed in the same way and were not associated with surface mold growth.

The best defense against damping off is to use a good soilless mix and to never use a dome, or if you do to prop it open, and make sure there's good air circulation and that the seeds are not too wet.

As for the environmental fungi that drop in, so to speak,

, it happens, and if they start to form a visible vegetative colony, just scrape off that colony. Those type of fungi also thrive where there isn't good air circulation and the mix is too wet.

Does that help?

Ruby · March 21, 2007

Quote:

Originally Posted by carolyn137

Ruby, you're describing the vegetative forms of normal airborne transmitted fungi, not pathogenic fungi.

They aren't a problem so just scrape off those areas and continue on. Had you been using peat pots, for instance, you would have seen sometimes the whole outside turn green with mold as well as the surface of the mix.

....

Does that help?

That helps IMMENSELY. I'll just be scraping up the mold now. Thank you! 8)

DavidinCT · March 21, 2007

I'm using Pro-Mix 'BX'.

Seeds are from half a dozen vendors. Have touches of mold which comes and goes in most cells. Tom Thumb peas are in 7" self-watering containers. The soil in those pots is a lovely British Racing Green.

March 21, 2007	#1
Ruby Tomatovillian™ Join Date: Jul 2006 Location: Southern California Posts: 44	Mold when starting seeds? I started some seeds (Craig's method) and after about 4 days I have some greenish mold growing on top of the mix (just a tiny bit in one cell). It's not dark green, but sort of greyish green with a little bit of white fluffy looking stuff (again, not that much but in more than one cell). This happened a couple weeks ago in a deeper flat of seed and I watered with a diluted hydrogen peroxide mixture to make myself feel better, but I wanted to find out maybe what I should actually be doing in this case. I don't know if it's just something in the air (yesterday and today have been cold and rainy). I'm pretty sure it's some combination of air temperature/moisture and possibly contaminated seed. Anyhow, I'm not too concerned, but I'd like to know the best way to treat this at the point I'm at now without throwing out the tray. I've taken off the plastic wrap (it was loose, for air circulation) because some seedlings are popping up. Seaweed extract? Hydrogen peroxide? Baking soda? Cinnamon? I thought it was a fluke the first time it happened, but it happened again so I thought I'd ask. Perhaps others have had the same issue.

March 21, 2007	#4
carolyn137 Moderator Emeritus Join Date: Jan 2006 Location: Upstate NY, zone 4b/5a Posts: 21,169	Ruby PMed me about this b'c I had sent her three tomato varieties and she told me that the mold was growing where the one variety was planted which suggested to her that the seed for that variety were contaminated with fungi, but not the other varieties I sent. So I'm glad to come here to see it was on top of the mix, as I assumed. While it's true that seeds can have adventitious fungal spores attached, and some may not be removed by Fermentation, those spores are NOT from fungi that make visible colored growth in mixes such as is being described. And spores for the genera and species that can cause damping off are in the mix, not seedborne. Ruby, you're describing the vegetative forms of normal airborne transmitted fungi, not pathogenic fungi. They aren't a problem so just scrape off those areas and continue on. Had you been using peat pots, for instance, you would have seen sometimes the whole outside turn green with mold as well as the surface of the mix. No need to treat such areas with peroxide, which doesn't work anyway, or with chamomile tea, the latter of which has been suggested to be used to prevent damping off. Remember that there's both pre and post emergent damping off and you don't even see the fungal growth when you see the first seedlings fall over with damping off but then may see the fine white filaments later. So I'm here to post b'c Ruby told me about her thread, and I'm here to hopefully clear up any confusion with normal environmental fungi vs pathogenic fungi adhering to seed surfaces. As I also told Ruby, the variety in question that I had sent her that had mold growing in the area has been grown from the same seeds by several hundred folks with no problems at all. And the two other varieties I sent her were processed in the same way and were not associated with surface mold growth. The best defense against damping off is to use a good soilless mix and to never use a dome, or if you do to prop it open, and make sure there's good air circulation and that the seeds are not too wet. As for the environmental fungi that drop in, so to speak, , it happens, and if they start to form a visible vegetative colony, just scrape off that colony. Those type of fungi also thrive where there isn't good air circulation and the mix is too wet. Does that help? __________________ Carolyn

March 21, 2007	#2
spyfferoni Tomatovillian™ Join Date: Feb 2006 Location: Utah Posts: 675	I've heard watering with chamomile tea is helpful for mold and crud. I'm sure others will say something about it. I haven't had to use it yet. Tyff

March 21, 2007	#6
DavidinCT Tomatovillian™ Join Date: Dec 2006 Location: Connecticut Zone 6B Posts: 88	I'm using Pro-Mix 'BX'. Seeds are from half a dozen vendors. Have touches of mold which comes and goes in most cells. Tom Thumb peas are in 7" self-watering containers. The soil in those pots is a lovely British Racing Green.