Lex
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mold :( How to properly moisten soil?

I made my first attempt at starting seeds indoors 3 days ago. I now have a nice, healthy carpeting of white fuzzy mold on the top of my peat pots (and broccoli seedlings poking out, yay!). I've seen from a few threds (e.g. [url=https://www.helpfulgardener.com/forum/viewtopic.php?t=33323]this one[/url]) that my pots are probably way too wet. Whoops. I kind of wondered if I might be overwatering when I set everything up.

I'm using a "soil" mix that seems to match the recommendations I've read in seed starting guides. It's made of sphagnum, peat, vermiculite, perlite, and I believe some sand as well. In reading through my guides again, I see that I'm supposed to "moisten" this soil before adding it to my pots, rather than "wetting" it.

The question I have is, how moist is "moist"? I know I need enough water to let the seeds germinate, but obviously it's quite possible to overdo it. Do you folks have any recommended techniques for properly moistening the soil without overwetting it?

If it helps to know, I'm germinating my seeds in peat pots tucked together in a deep foil baking pan, with saran wrap over the top. I removed the saran wrap when I saw the mold, but that doesn't seem to have killed it.
Last edited by Lex on Sun Mar 20, 2011 5:22 pm, edited 1 time in total.

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Kisal
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I was taught to take a small handful of the soil in one hand and squeeze it tight. When you open your hand, moist soil will stay compressed in a little "lump" for just a few seconds, and then it crumbles. If it's too wet, it just stays as a lump, or at least doesn't crumble very soon. If it's really wet, you'll have water in your hand. If it's too dry, it won't form a cohesive lump at all.

Someone else might be able to give you a better explanation. That's about the best I can describe it. :lol:

I don't like peat mixtures for seed starting. Truth is, I don't like them at all for growing plants. The mixtures are usually far too acidic, and the peat holds water for too long. But if you once let it dry out, you'll have a devil of a time getting it moistened again. I think I'd use plain sand before I'd use a mixture with a lot of peat. And peat pots kill plants ... period. It's the nature of peat to be either too wet or too dry, with no happy medium. JMO. ;)
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arisachu
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Kisal wrote:I was taught to take a small handful of the soil in one hand and squeeze it tight. When you open your hand, moist soil will stay compressed in a little "lump" for just a few seconds, and then it crumbles. If it's too wet, it just stays as a lump, or at least doesn't crumble very soon. If it's really wet, you'll have water in your hand. If it's too dry, it won't form a cohesive lump at all.

Someone else might be able to give you a better explanation. That's about the best I can describe it. :lol:

I don't like peat mixtures for seed starting. Truth is, I don't like them at all for growing plants. The mixtures are usually far too acidic, and the peat holds water for too long. But if you once let it dry out, you'll have a devil of a time getting it moistened again. I think I'd use plain sand before I'd use a mixture with a lot of peat. And peat pots kill plants ... period. It's the nature of peat to be either too wet or too dry, with no happy medium. JMO. ;)
I peeked in here because I have been having a few mold problems and wanted to see if anyone had any tips on how to get rid of it, but lo and behold, I seem to have found the answer to my other problem - mainly keeping my plants alive in the first place. My Miracle Gro seed starting soil is 90-95% peat mixture. :( I have been having problems with getting the soil to stay properly moist. I'm glad you said this.

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Halfway
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Warming the water will help peat absorb it. Dry peat is a pain in the @ss!!
Zone 4a.

bangstrom
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I made some suggestions about soil microbes in the thread you mentioned but peat pots are subject to mold under the best of conditions. Mold issues are much less of a problem in plastic.

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Mold issues are much less an issue if you get some of the ecologically amended soils or add the biology;[url=https://web.pppmb.cals.cornell.edu/resourceguide/mfs/01bacillus_subtilis.php]Bacillus subtilis[/url] is one, [url=https://greenmethods.com/shop/buy-goods/3/]Trichoderma[/url] is another. The bacteria is about the most common in compost, so there's another way to get it done.


HG
Last edited by The Helpful Gardener on Sun Mar 20, 2011 5:12 pm, edited 1 time in total.
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rainbowgardener
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Your soil may not be ideal, but it will work fine for you if you get it out of the peat pots. You need plastic pots (even plastic drink cups, as long as you make drainage holes). And you need air circulation. The peat pots all pressed up against each other just compounds the problem.
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DoubleDogFarm
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I've been mostly bottom watering with a concoction of horse manure, beer extract and hydrolyzed fish fertilizer. No issue with mold or damping-off. :D

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Lex
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Thanks for all the tips, folks! It sounds like my problem is twofold: I watered way too heavily and I need to use plastic containers. I'll try again with solo cups or something similar. As it turns out, my mix us innoculated with micorhizzhae, but I guess that wasn't any match for my heavy hand with the watering :)

I'm still at a loss for what technique to use to get the right amount of moisture into the mix. I think if I just water the top, the lower levels will stay bone dry. My current idea is to layer the soil into the pots a but at a time, and mist on a little water at each kevel with a spray bottle. Does anyone know of a better way?

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I bottom water my seedlings by filling the tray with water about halfway up the sides of the containers. You'd be surprised how much water a tray full of seedlings can absorb! Sometimes, I have to fill the tray with water a second time, to get all the pots well watered. If the surface of the soil is dry, I mist it with a spray bottle, to dampen it slightly.
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rainbowgardener
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To start with, before anything is planted in the soil, I pour water in the top and then stir it around, to make sure the soil is moistened. After that, once seeds/ plants are in, like Kisal, I only bottom water. Everything is in trays and I just pour some water in the tray and let them soak up what they need. Gives you a lot better control that way.
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applestar
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As described, I always fill my containers with pre-moistened soil.

For those bone dry mixes that come in a bag, hands-down the best method I know is to add bath-hot water (i.e. hot enough to be steamy but not boiling hot) to the bag, twist the top tightly with lots of airspace, and shake vigorously.

If you have a large amount and only using a small portion, transfer to a different bag. Somebody humorously dubbed this the "Shake 'n' Bake Method." :lol:

The dried out mix will absorb more moisture than you might think, but start with smaller amounts and add more after shaking as necessary. This way, you won't over-moisten the mix and have to adjust backward (always save some dry mix on the side for this purpose).

If you want to prepare a large amount, I'd still do this in batches small enough for to hold and shake the moistened mass without hurting yourself.

Oh yes, don't forget to let the mix cool down before planting, especially if you are uppotting plants. You can sow some warmth-loving seeds directly into the warm mix.

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The grower at my current job puts it thusly...

"You can always water more, but you can't take it back."

More plants killed with more than less....

HG
Scott Reil

Lex
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The plot thickens.

I went to start fresh last night with a set of plastic butter tubs with drainage holes cut. I went and got my bag of potting mix which is still dry -- it's the leftover from last time. The entire surface of the mix was covered in the same white fuzzy mold! I scraped off the mold, but it's completely penetrated the mix, so I decided not to use it. Does anyone know what would cause my mix to mold like this?

I wanted to get another batch of seedlings going, so I decided to use the bag of play sand I had in the garage. I planted the seeds in moist (but not drenched) sand that I loosened up as much as possible. We'll see if that works.

So now I'll have seedlings growing in a medium completely devoid of fertility. I have a bag of organic fertilizer. Should I sprinkle it on after the seedlings come out, or can/should I mix the fertilizer with water and pour it in? Does anyone know of a good (organic) liquid fertilizer for seedlings?

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applestar
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From what you've described, I don't think it's mold in the sense you are thinking of. I think it's fungal hyphae/mycelium. In other words, they're beneficial to the soil.

I believe we're going to see this more often as adding mycorrhizae in the premium potting soil becomes more prevalent among the bagged soil manufacturers.

I see you are from Massachusetts. Are you perhaps using Master Gardeners brand Gardeners Gold potting soil or a Coast of Maine product? I like their premium organic potting soil.

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Yes, I think Apple nailed it, not mold at all. What is the brand of mix you are using?


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Lex
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Well, it definitely has mycorrhizae in it. It's [url=https://www.newpromix.com/index.asp?ref=page_veggie_features]ProMix herb and vegetable[/url]. The stuff I saw was this wispy white fuzzy stuff in patches all over the surface of the soil. Maybe it's just the mycorrrhizae?

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Wispy white fuzzy could just be sapprophitic fungi (soil decomposers), but it might not be...

Damping off is the bane of seedlings and that's mostly about moisture (as the name implies). Less water is generally a good idea; they will let you know if they need more...

HG
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stella1751
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Lex wrote:Well, it definitely has mycorrhizae in it. It's [url=https://www.newpromix.com/index.asp?ref=page_veggie_features]ProMix herb and vegetable[/url]. The stuff I saw was this wispy white fuzzy stuff in patches all over the surface of the soil. Maybe it's just the mycorrrhizae?
Lex, where did you find ProMix? I bought a huge square of it at a garage sale about ten years ago. ($5!) It lasted me eight years, and I loved it! I've been trying to find more, but I think the person I bought it from must have moved it in from another state.

I never did have a problem with mold or fungi on it, but it was bone dry when I bought it, and I only moistened the stuff I used.

BTW, I never cover my seedlings; I just water the soil before planting, letting it soak until the tops turn dark, and then I mist the tops morning and night until I am certain all the seeds that are going to germinate have sprouted.
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Lex
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Oh, I got it at Home Depot here in Massachusetts. It was right outside in the garden area with the other soils.

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Lex wrote:Oh, I got it at Home Depot here in Massachusetts. It was right outside in the garden area with the other soils.
It must be a regional thing, then. If you're ever driving through Wyoming . . .
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