Help!
So the past 3 seasons I went with perlite and hydrogen peroxide mix which seemed to work but took up space and when it came to finding my seeds it was a messy tedious process. But I saw videos where people say the paper towel method works well etc etc… fast forward a bit… mold is causing me problems and has become tedious. How long and how much hydrogen peroxide should I bathe them in before reapplying to the paper towels?
I pulled out the paper-towelling part way through last year’s stratification due to overwhelming mold (mostly black and rhizomatous) and found that a few drops more peroxide broke it up. Germination proceeded without the towelling, and it was so much easier to see what the individual seeds were doing come planting-out time.
I change out the paper towels at the slight sign of mold. But that’s less than ideal with higher seed counts
This spring I tried refrigerating them in 2oz condiment cups after a good soak in a hydrogen peroxide solution. Spritzing them occasionally throughout the stratification period, again with a hydrogen peroxide solution, to keep moist.
It worked well with the batches I remembered to spritz
If you’re not in California, you might be able to still obtain Captan. Eons ago, when we could find it here, it was what I used to prevent mold on the towels. It was what was suggested for the purpose at the time.
What did you do instead of the toweling sorry? I have been just taking them out cleaning them up and placing them in a quick water/hydron peroxide bath, then dipping the new paper towel in the solution to try make it last longer before changing again. Stratification is always my least favourite bit of work in the process. I find it such a chore…. I wonder what large scale breeders do? I also wonder if the minor mold I had will help them germinate when the time comes… could be worth it?
Looks like I could get it for a very high price, not sure it’s still legal here
It got really, really gross right before the new year, so I pulled them out, rinsed them in tepid water thoroughly, washed out the baggies, and back into the fridge bare-bagged (with a few more drops of peroxide) for a week-ten days while I prepped the boxes, then I planted directly outside in January. I figured the varying temperatures would help.
Then it snowed and stayed around freezing for a week. lol
I got sprouts in due time, but also large swathes of empty rows. Your mileage may vary.
Nature is tricksy, and always a surprise.
I think I will just have to persevere for this year. I doubt I will ever have this volume of seeds again. Life will Most likely get in the way…
I know from several sources involved in rose breeding that Chinosol tablets were used in the past. This preparation was available in pharmacies. However, it was withdrawn from the market due to health risks. Now there is NeoChinosol available, which has a different composition. This product should also disinfect well but is not suitable for our use, as it is said to prevent germination. I have never used either product myself.
If needed, I only use hydrogen peroxide 3% solution, but it is important to note that the decomposition rate of hydrogen peroxide (H₂O₂) depends heavily on factors such as temperature, purity, and storage conditions. Under ideal conditions, such as cool storage and original packaging, decomposition is very slow and the shelf life is over a year, while contamination and heat can significantly accelerate this process and thus reduce its effectiveness.
Fungi break down the outer seed coat (achene), which can enhance germination. The issue is that not all fungi are compatible with the stratification process, so allowing the seeds/paper to grow a lot of mold is a bit of a gamble: it may enhance/speed germination, or it may end up killing the seed inside the achene. My personal experience suggests that 95% of the time, the mold does no damage — at least up to the point where the root pushes through the achene — but that other 5% of the time, the mold is capable of killing the seeds, resulting in low-to-zero germination.
I used to ignore mold during cold stratification, considering it a natural part of the process unless it got to be severe and/or the roots started to appear when the achene split. If I spotted roots, I pulled the seeds out promptly and sowed them. Following this protocol, I rarely lost seeds to mold damage.
I don’t recommend my method for you, and only as a last resort for frustrated cold zoners where snow and ice. I am an outlier in my method for temperature for stratification (partial freeze and for months and then basement ambient cycles and finally heat mats).
No fungus infections.
Except last year and only on one variety of seedling (and everyone - an obscure heritage hardy rose). No treatment shrivelled and passed.
No peroxide normally used, except the time l was trying to guess and imitate Dr Svedja ambient pre cool stratification method.
I knew l was likely heading for disaster untreated, so dump seeds in 3-5% diluted pharmaceutical grade wash and removed, into pearlite and left at basement ambient for a week or so. Was a wee bit of a fungal disaster.
Back to the old method. I still use pearlite and can’t blame anything on it. Once germinated l prick the seedlings out at the proto (cotelyon sic) leaf stage very carefully and transplant in MG mix - expensive but convenient, peat moss, bit of pearlite wood chips / fert.
No fungus but lots of moss as seedlings grow within it.
Yeah I tried to convince myself it might actually help. But will try to not let it get too out of hand. I would always get a very little bit with old method just at the 3 month point as I took them out of the fridge. However it never seemed to cause any harm
I became so disappointed with my germination percentage, that I have returned to my original method of sowing in pots and leaving them outside.
From my experience the amount of moisture in the bag with the paper towel and seeds matters very much in how quickly and to what degree mold develops. I do not use any treatment at all, just rinse with water. But I have learned to put less (I mean a lot less) moisture in the bag. If the paper towel feels lightly dampened it is plenty. As soon as it starts to feel more moist it will soon develop mold.
I have yet to put too little moisture, damaging the seeds, so I cannot say how low a level it would have to become to actually do that. I guess you would have to experiment with extra seeds you would risk losing.
But for me I change the paper toweling once or twice during the winter: usually twice is because I have moistened it a bit too much. I am trying to avoid this, as I have increased my numbers a lot and can’t afford to keep repeating the process. I have them stored from when I eventually get the hips processed (usually Late Sept to early November) until I find a germination in that bag (anywhere from January through Late April).
I would be curious to know if the peroxide would be beneficial in those instances where I get it slightly too damp in the bag.
Duane
Peroxide (H2O2) would add water as it splits into H2O(water) and O(-xygen). That’s my thinking behind adding a few drops to dry towel containing the seeds, anyway.
Maybe the oxygen supports mold growth?
Yes as I have had to do one rebag all ready and I have a lot more seeds than previous years I am also worried about the amount of re bagging. If the germination rates are good I will just have to suck it up
What method did you use to stratify your seeds?
Damp paper towels in ZipLoc bags, then into the fridge for at least 12 weeks.
Did you have to change them often, I don’t feel like I’m soaking them, I wring out the paper and have hydrogen peroxide in the mix! But I only change it when the mold gets a ring around a few seeds
Sorry for all the questions, but I have more seeds this year than my past 3 put together by a lot. Once you removed them from the paper towels what medium did you put them in? Did you also rub of or remove visible mold after paper towel stage