possible to over dry seeds with too many dry packs when storing seeds

[Gr33nSanta]

Is it possible to over dry seeds with too many dry packs when storing seeds?

I really want to make sure I have this dialed in I am about to make seeds that I know I wont grow for some years and there is a lot of good seeds in my collection I dont want to lose them to poor storage.

I have 1 dry pack in each ziploc bag containing anywhere from 2 to 50 seeds in each ziploc bag and everything in a larger ziploc bag with a few more dry packs. Tucked in the corner of the fridge.

 

[MJPassion]

I would think that desicant packs could be overdone but can't be sure, myself either.
I know far a fact that for seed to remain viable it must maintain about 7% to 11% moisture content. Not sure if the seed has a protective mechanism to inhibit moisture loss.

Excellent question Gr33nSanta.

 

[soundman]

Good question. I used small packets in mason jars vacuum sealed and stored in fridge for several years without problems. Based on my non scientific experience, I don't think they can over dry seeds.

I will watch this thread for more opinions.

 

[neongreen]

No it isn't. Silica gel will never remove all of the moisture, and seeds store best in close to or zero moisture environments. It's actually very hard to over-dry seeds.

Edit to add: and whilst the fridge is usually a very dry environment, plastic bags are no barrier to the movement of moisture. Ideally store your seeds in mason/kilner jars, in the fridge, or any other environment where the temp is low, but more importantly stable.

 

[Easy7]

Never seen ice crystals forming around frozen seed. Only bad thing about freezing is the outer shell gets fragile.

Always used rice.

 

[Betterhaff]

I don’t put the desiccant packs directly in with the seeds. Seeds in baggies, baggies in mason jar, desiccant packs in mason jar, mason jar in fridge.

 

[AgentPothead]

There a thread over https://www.icmag.com/ic/showthread.php?p=3835224 about seed storage. He seems to be using rice instead of desiccant packs though.

 

[neongreen]

I don’t put the desiccant packs directly in with the seeds. Seeds in baggies, baggies in mason jar, desiccant packs in mason jar, mason jar in fridge.

Yep. That's the way to do it IMHO.

 

[neongreen]

Never seen ice crystals forming around frozen seed.

Yeah, but it's ice crystals inside the seed that do the damage.

Only bad thing about freezing is the outer shell gets fragile.

The only real downside is if the power goes out long enough for the seeds to defrost. Then you are stuck with a bunch of seeds that need to be germed in a hurry, although I suppose you could keep them in a fridge for a bit, but it certainly wouldn't be a good idea to freeze them again.

Of course you could have an emergency backup generator, if you were really serious about it.

 

[biomassa]

I know far a fact that for seed to remain viable it must maintain about 7% to 11% moisture content. Not sure if the seed has a protective mechanism to inhibit moisture loss.

As I have read so far - you can and should go lower ( A Belated Green Revolution for Cannabis: Virtual Genetic Resources to Fast-Track Cultivar Development )

Considering the complexities associated with Cannabis germplasm regeneration, much attention has been directed to efficient methods of seed storage. Duration of storage, temperature, and seed moisture content are all variables which can significantly affect the viability of Cannabis seeds (Small and Brookes, 2012; Parihar et al., 2014). Common practice for short-term seed storage is 4°C with a moisture content of 6% (De Meijer and van Soest, 1992; Small and Brookes, 2012; Mankowska and Silska, 2015), while for longer periods of storage >3 years, seeds are held at −20°C with ~4% moisture content (De Meijer and van Soest, 1992; Mankowska and Silska, 2015). Cannabis seed appears to have orthodox storage behavior, and the ability to withstand periods of up to 66 months after desiccation with minimal effects on seed viability (Small and Brookes, 2012; Parihar et al., 2014). Nevertheless, systematic evidence for the long-term viability of Cannabis seed is lacking.

so the best conditions should be:
< 3 years = 4°C at 6%
> 3 years = -20°C at 4%

 

[neongreen]

so the best conditions should be:
< 3 years = 4°C at 6%
> 3 years = -20°C at 4%

I think that's a significant underestimation of what is possible with the fridge.

There's no need to freeze if you store carefully in the fridge and don't plan on storing for longer than 10-15 years. I get close to 100% germ rate with seeds I bought 13 or so years ago (kilner jars/gel/fridge), and I imagine they will still mostly germ for years to come, although it is now becoming a priority to reproduce the harder to get strains.

I'm sure 20-25 years is possible before germ rates fall below 50%, based on what I've heard said on here, but of course that is assuming you have very healthy seeds to begin with.

I've always had to open my jars (8 of them in the fridge right now) and mess with them every once in a while (I try not to), but if you just left them alone, I suspect, you could store for even a few decades more than this, just with basics (kilner jars/gel/fridge) and leaving it alone.

At least one study has shown that it's not so much temperature (as long as it's not too much), but variations in temp (and probably humidity) that will erode viability over time. That also makes a few feet below ground (if you can keep moisture out) a good place to store seeds.

That's also the reason I split my collection into lots of jars - so if I need something I don't have to disturb lots of seeds in the process.

 

[MJPassion]

As I have read so far - you can and should go lower ( A Belated Green Revolution for Cannabis: Virtual Genetic Resources to Fast-Track Cultivar Development )

so the best conditions should be:
< 3 years = 4°C at 6%
> 3 years = -20°C at 4%

Thanks for posting that!

If any of yall have seeds in your auto defrost freezer, they get a year older every time the freezer runs its defrost cycle.

 

[7Scorpions]

Have been popping brick seeds that r a decade old but still have a nice layer of shake and stems i guess protecting them? Shits were stored in a ziplock in a garge that gets up to 120 degrees at times but still germ over night and then i have seeds that ive got for 100 bucks a pack that cant pop for shit

 

[brown_thumb]

Yeah, but it's ice crystals inside the seed that do the damage.




The only real downside is if the power goes out long enough for the seeds to defrost. Then you are stuck with a bunch of seeds that need to be germed in a hurry, although I suppose you could keep them in a fridge for a bit, but it certainly wouldn't be a good idea to freeze them again.

Of course you could have an emergency backup generator, if you were really serious about it.

...and an alarm to tell you the primary freezer is failing and have a backup freezer to move the seeds to if one freezer fails.

 

[brown_thumb]

Thanks for posting that!

If any of yall have seeds in your auto defrost freezer, they get a year older every time the freezer runs its defrost cycle.

Not if one keeps the seeds in an insulated ice chest within the freezer. The ice chest greatly moderates temperatures. In fact, one could probably leave the freezer door wide open for 20+ minutes without significantly affecting temperature within the ice chest.

 

[neongreen]

Not if one keeps the seeds in an insulated ice chest within the freezer. The ice chest greatly moderates temperatures. In fact, one could probably leave the freezer door wide open for 20+ minutes without significantly affecting temperature within the ice chest.

That's not a bad idea actually. I might have to steal it for my pollen collection which is currently mostly kept in a large tupperwear box in the freezer.

 

[brown_thumb]

I think if I was going to freeze seeds for posterity I'd first find a way to estimate the moisture content of the seeds and adjust accordingly. Once I have that right, I'd put a few seeds per baggy and toss them on top of some dry ice in an ice chest for a few minutes before QUICKLY moving them to frozen Mason jars with desiccant packs. Surely, a quick freeze is better than slow freezing to minimize cellular damage. Keep the jars within an ice chest inside the freezer. It seems the best AFFORDABLE way to ensure longevity of seed viability.

It doesn't matter much to me though. I'll be gone before any reasonably cold-stored seeds fail anyway... 10-15 years?