Fungicide for stratifying seeds

[Paul G]

Starting a ton of different seeds this winter, and as I've been researching, several different sources recommend occasionally spraying a fungicide inside the ziplock bag while the seeds are stratifying in the fridge. Any reason why I couldn't/shouldn't use the one pictured below?

Cheers,
Paul

 

[Wires_Guy_wires]

Because a copper overdose can inhibit growth?
I only use antibiotics in citrus seeds, the rest usually doesn't have any fungal issues.

I think it's better to not use antifungals if it's not needed. Most of the times, seeds get fungal issues for three reasons: there's too little air flow, or the medium is being too wet, or it's the wrong temperature.
Sphagnum and peat with perlite are great stratification and sowing media. It's rare ro get fungal issues even if all the conditions are right, unless you're growing citrus..

 

[sorce]

I wouldn't use it either.

Better to not mask those underlying issues,

there's too little air flow, or the medium is being too wet, or it's the wrong temperature.

I don't know if it's actually a thing....

But if a tree is going to be prone to fungal attack, let it die anyway.

For a farmer, a couple more sprays in the season is all it takes to fully grow a plant prone to fungal attack (weak).

For us, a plant prone to fungal attack adds 150 years to a 25 year project.

Let em die!

Sorce

 

[Wires_Guy_wires]

I wouldn't use it either.

Better to not mask those underlying issues,

I don't know if it's actually a thing....

But if a tree is going to be prone to fungal attack, let it die anyway.

For a farmer, a couple more sprays in the season is all it takes to fully grow a plant prone to fungal attack (weak).

For us, a plant prone to fungal attack adds 150 years to a 25 year project.

Let em die!

Sorce

Unfortunately it doesn't work like that with seeds. Past the seedling stage though, it does work like it do. The reason why I'm ditching black pines.

 

[0soyoung]

I use 2 tablespoons of 3% hydrogen peroxide (from the local grocery/pharmacy) in a quart of water. I use it instead of bleach to sanitize the seed. I use it instead of tap water to dampen the paper toweling I use in stratify them.

While I agree that

Most of the times, seeds get fungal issues for three reasons: there's too little air flow, or the medium is being too wet

the peroxide solution has been an effective way for me to recover from my mistake. Peroxide (H2O2) releases reactive oxygen, killing bacteria and fungal spores, and turns into just ordinary water (H2O).

 

[Paul G]

Thanks for the feedback everyone

 

[Wires_Guy_wires]

I use 2 tablespoons of 3% hydrogen peroxide (from the local grocery/pharmacy) in a quart of water. I use it instead of bleach to sanitize the seed. I use it instead of tap water to dampen the paper toweling I use in stratify them.

While I agree that

the peroxide solution has been an effective way for me to recover from my mistake. Peroxide (H2O2) releases reactive oxygen, killing bacteria and fungal spores, and turns into just ordinary water (H2O).

1:50 bleach solutions work wonders! I use it on imported seeds that might introduce foreign bacterial pathogens, but I put a 5 minute max cap on that treatment. As soon as I wash the bleach solution off (it takes 4 rinses with tap water) I introduce fresh spores from the air onto basically sterilized seeds. That's where the issues tend to start, so sometimes no treatment at all is better. Peroxide is great for these kind of things too. In most cases I don't even dilute it, it breaks down rapidly in sunlight and when exposed to air.
But these treatments - bleach excluded - are aimed at the effects, not at the cause ;-)

The cause is usually that there's a bunch of starches stored in a seed, and the perfect conditions for fungi to munch on it before the seed becomes active.

@Paul G What seeds are you germinating? Pine seeds for instance usually don't need antibiotics. Some antibiotics are so strong that they inhibit plant growth, so it might be better to discuss whether you even need this kind of stuff or not.
Also, since everybody is cool talking about soils again, I think it's also pretty good to discuss sowing media. Spring is coming up and people are filling up their fridge drawers!

 

[Leo in N E Illinois]

I've used hydrogen peroxide solution as a biocide for seed in plastic bags in the refrigerator. It breaks down quickly into simply oxygen and water. You do not have to be precise with dosing, you can even use it up to about 3%, which would be straight out of the bottle for pharmacy grade peroxide (sold in grocery stores and big box stores in the first aid section of the store). The "better" dose rate is about 1% as active peroxide. It all breaks down into oxygen and water in less than 24 hours, with most gone in 1 hour. If you don't reopen the bag, the insides will stay mold and fungi spore free until you open the bag again.

Note: there is an agricultural grade hydrogen peroxide that is 30% active. This is high enough to be physically dangerous to human skin. It will burn you if you come in contact with it. It is also strong enough that care must be taken to dilute it to the desired strength. The finished dilution should be about 1% for use as a fungicide / bactricide for seeds in stratification.

 

[Paul G]

1:50 bleach solutions work wonders! I use it on imported seeds that might introduce foreign bacterial pathogens, but I put a 5 minute max cap on that treatment. As soon as I wash the bleach solution off (it takes 4 rinses with tap water) I introduce fresh spores from the air onto basically sterilized seeds. That's where the issues tend to start, so sometimes no treatment at all is better. Peroxide is great for these kind of things too. In most cases I don't even dilute it, it breaks down rapidly in sunlight and when exposed to air.
But these treatments - bleach excluded - are aimed at the effects, not at the cause ;-)

The cause is usually that there's a bunch of starches stored in a seed, and the perfect conditions for fungi to munch on it before the seed becomes active.

@Paul G What seeds are you germinating? Pine seeds for instance usually don't need antibiotics. Some antibiotics are so strong that they inhibit plant growth, so it might be better to discuss whether you even need this kind of stuff or not.
Also, since everybody is cool talking about soils again, I think it's also pretty good to discuss sowing media. Spring is coming up and people are filling up their fridge drawers!

Again, thanks for the advice. I'm trying about a dozen different species, including JBP, dawn redwood, flowering apricot, hornbeam, and a shit ton of Acer P. Not very hopeful for the last one, based off of everything I've read, but who knows. Last year I focused on cuttings, and I had pretty good results once I learned not to get greedy and to stick with the new, tender shoots. This year it's seeds.

 

[0soyoung]

With a.p. (and any acer's, for that matter) seeds, cut a few in half (across the plane of the samara) to see if they have an embryo inside. Unviable seeds are hollow.

Also, if you are getting into growing from seed, Dino's book (and it's two supplements) on the subject is available in the BNut Resources.

 

[penumbra]

Another one here using peroxide.

 

[Arlithrien]

I dipped my seeds in diluted peroxide solution to kill any existing fungal spores. Then I coated them in fungicide before popping them in the fridge.

My understanding is it's safe to spray them so long as you do it before they germinate. After, try to avoid it.

 

[TN_Jim]

Peroxide is acidic
Bleach is alkaline

Seems like most maples prefer a slightly acidic environment, don’t know if that’s really true.

However, maybe bleach treatment would be my approach to species not best in acidic soil.

Whatever approach, the entire working surface and tools sterilized can definitely be important in my experience germinating seeds

 

[rollwithak]

Damn. I’m just taking my chances with all of my seeds this winter...... guess I’ll learn my lesson.

 

[Canada Bonsai]

I've used hydrogen peroxide solution as a biocide for seed in plastic bags in the refrigerator. It breaks down quickly into simply oxygen and water. You do not have to be precise with dosing, you can even use it up to about 3%, which would be straight out of the bottle for pharmacy grade peroxide (sold in grocery stores and big box stores in the first aid section of the store). The "better" dose rate is about 1% as active peroxide. It all breaks down into oxygen and water in less than 24 hours, with most gone in 1 hour. If you don't reopen the bag, the insides will stay mold and fungi spore free until you open the bag again.

Thank you for this! I would just like to clarify please:

I can soak my seeds (and sphagnum moss) in that solution (prior to stratification), then squeeze the liquid out the sphagnum moss like i always do, and then toss it all into a sealed ziplock bag?

(I have been rising the seeds and moss in plain water after the hydrogen peroxide solution -- this now seems like an unnecessary step!)

I'm guessing the length of time for the soak in the solution becomes irrelevant? It can be as little as 30 seconds for example?

Thank you

 

[River's Edge]

I agree with the advice provided by Leo, I would like to add a couple of comments!
If you are concerned about the condition of the seed and wish to reduce the chance of fungal issues during stratification then I would do the following!
Prepare a solution of dilute Lime Sulphur ( 1 part Lime Sulphur to 10 parts water) and soak the seeds for 30 minutes. Rinse the seeds in plain water after the soak and pat the seeds dry after rinsing!
Now proceed to use the hydrogen peroxide solution to dampen the paper towel or sphagnum moss before wrapping the seeds and storing in the fridge! Strive for damp not wet conditions. Tiny droplets condensing on the inside of the refrigerated bag. I check the bags to ensure proper moisture level every two weeks, using the hydrogen peroxide solution to dampen if required!
I have found better results with laying out the paper towel, a light layer of shredded sphagnum moss ( squeeze out the excess moisture real well before spreading on the paper towel), sprinkle the seeds and roll up the paper towel. I use a spray bottle to dampen the outside of the paper towel roll before placing in the zip loc bag. This ensures dampness and high humidity without excess moisture inside.
Just some further suggestions of one approach.

 

[bwaynef]

I've had some issue with fungus growth while in stratification, particularly warm stratification. I'd also bought some Captan to use for just this scenario ...but had hesitated using it because I didn't really WANT to use a fungicide. When met with the first signs of fungal growth in stratifying seeds this year, I cleaned the seeds, soaked in h2o2 & h2o, LIGHTLY (i mean SUPER lightly!) dusted the seeds with Captan and shook them around in a disposable cup, then put them back into a moist paper towel in a baggie in the fridge. I don't love the solution, but its proven to be effective so far.