Starting first attempts at cold stratification

Hopefully goes well. I'm starting to get worried that I can no longer rely on winters going my way to get native plants to start, so I want to try to teach myself how to force it.

I collected some small soil samples in some ziploc bags from the general areas I intend to put them, so I hope they'll work out that way. Everything is labeled. I have 8 that I just put in the freezer & intend to take out in July- Cucumber Magnolia, False Indigo Bush, Tamarack, Blueberry, Deerberry, American Cranberrybush, Yellowwood Tree & Eastern Sweetshrub. Two seeds per bag, though I got a bit paranoid about how long the Magnolia seeds would last after opening the fresh-seal pouch they came in & there may be a lot more of the Blueberry & Deerberry, given how small the seeds are. The plan is to get the seeds to wake up, then just very carefully dump the bags back out in nature & hope they set in before winter.

Any tips or suggestions? How easy/ hard is it bound to be to get this to work?

This is coming from someone who has only done cold-stratification outside, so take it with a grain of salt... Even though the seeds experience freeze-thaw cycles outdoors, artificial cold stratification usually happens in the fridge. Apparently, that's cold enough.

My other tip is, check for other germination requirements besides cold. Some of my seeds had to be knicked or scratched with sand paper, others had to be soaked for 24 hours before sowing.

Good to know on the refrigerator. I just moved them all to there. Hopefully, any additional work with the rest of the seeds won't be an issue- a lot of them are pretty small &/ or fragile & anything I got from Prairie Moon already comes with those steps pre-done for you. The only one with particularly big, thick seeds was the Sweetshrub & I got one to grow before without scarification, so it should be fine. I guess it's just a reminder to be mindful of in the future.

I guess, say a prayer to the little people for me, or whatever Manitou in Mediwiwin whose job this is. Lol

Cucumber Magnolias might be getting ready to start growing after just 3 weeks. After a couple of days in the bag, they swelled up & turned bright red. I began noticing cracking & what I was worried might be some sort of mold/ fungus on one seed, but after messing around with them through the bag, it turns out that the outer layer turned to mush & sloughed off, leaving a hard, black seed underneath. I think they developed in the dirt that way, because when I received them, I was supposed to have gotten 5 seeds. Instead I got 3 & a bunch of shattered pieces/ dust. No apparent black seeds were under that. I thought the Yellowwoods were getting close too, but I really am not 100% sure.

I read somewhere that you should open the bags periodically to get a fresh exchange of air & let out condensation. Also, giving little spritzes of hydrogen peroxide- water 1/5, 20% solution. I decided that that part should be unnecessary, since they're native seeds in native soil & should be adapted to all that already. Opening the bags kind of made the condensation worse, to be fair, but sliding the dirt around inside the closed bag relieves that fine.

Depending on where you are, I'd be afraid waiting until July to set the seeds loose into nature. One because they might not have enough time to establish before winter, and two because that's the hottest time of year and you'd need to keep on top of babying the little sprouts that evolved to germinate months earlier in the spring.
One comment on the blue false indigo: I also initially thought it needed a long cold stratification until someone reminded me that 10 days is enough per Prairie Moon. And indeed, I pulled them around that time and had a great germination rate (granted they also need a nick and 24 hr warm soak.)

It's not false Indigo flower, it's False Indigo Bush, Amorpha Fruticosa. I've been having so much trouble figuring out the wildflowers, I didn't want to sacrifice any of them to this experiment, anyway.

Seems like a lot of work and worry.  I first research to verify the proper temp (meaning below 32 F or above it) and length of time needed for stratification, then I place the clean dry seeds in a sealed bag, label and date the bag and put the finish date on it and I put the bag in the deep freezer for the appropriate amount of time.  Works almost every time with high germination rates.  When I take the seeds out of the freezer I spread them out in a pan so they can acclimate to ambient temperature.  Then I sow in flats or direct sow at the appropriate time.

Because of the fact that I only work with local and regional native seeds, the assumption is made that the seeds naturally experience a deep freeze during winter, as opposed to only cold, slightly above freezing temperatures and continuous high humidity environment that a refrigerator creates.  I do not deal with plants that are not meant for my climate, and I do not do houseplants, so my issues are quite simplified.

Note that some seeds need a double stratification period, and as already mentioned some seeds need to be scarified.  Some seeds have a very long dormancy period that can be tricky to break.  Some seeds have a combination of these issues.  This is why I always do a quick check on germination procedures for particular seeds.  If it is too complicated I just skip it and move on to something else that interests me.  There are many things out there that I would love to acquire that are fairly easy to grow, more than I could play with in my lifetime, so I do not need to get hung up on anything complicated.

The only seeds I have had 100% failure after years of germination attempts and using every method imaginable to break dormancy has been seeds of currant cultivars.  It was mainly just a curiosity project then I got obsessed about it after experiencing constant failure (I do not like to fail and I am inherently stubborn, which makes for a deadly combination which has led to many wasted hours in my life).  A tough nut to crack, I finally gave up and moved on to other things.

Tom, that is interesting that the seeds will germinate after dry cold (rather than moist cold) stratification. Why do you prefer the fridge/freezer over outdoors? Just curious.

With apple seeds my best luck came by planting the seeds late in the fall in the ground and covering with a screen. But many of those were apparently eaten after I took off the screen. I'd guess that what germinated was a very high percentage of the seeds. None of them were scarified.

If you plant them in soil and the ground freezes the temperature of the seeds won't go below 32° F.

As recently mentioned elsewhere, I accidentally germinated a Crategus schraderiana - well it germinated itself - by dropping in muddy compacted gravel and driving a car over it twice a week for a year or so.  I tried mimicking the digestive system of a bear by soaking in hot vinegar and sandpapering the seed coat, then sowing in leaf mould and leaving out all winter... maybe I gave up too soon but these sorts of methods did not work!

OK, I got my first success today, with the Amorpha Fruticosa having sprouted in the bare clay.

I looked into it & it would appear that most of the rest of them haven't sprouted yet because they prefer temps of 65°+ Farenheit, so I'm removing them from the refrigerator & hoping for the best. Only one apparently required scarification, which I never did, though the seeds took on water, anyway, so I think they're fine? Those were the Yellowwoods.

Hah! Caught the Yellowwood trees, just now. I hope the rest quickly follow suit.

Just had the Tamarack sprout. I had two seeds in there, but I could only find the one which had sprouted & ran out to plant that somewhere shady & fertile, since we're going to be stuck in high 80s- mid 90s for much of the next week, on & off. Now, all that's left is Cucumber Magnolia, Eastern Sweetshrub, Deerberry, Blueberry & American Cranberrybush.

That being said, I'm not sure if I lost some of the seeds. These are Cucumber Magnolia & Sweetshrub. Great if someone could take a look & give me a second opinion.