In a Tupperware container in the back of the fridge
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Hi.
I am considering long term storage for seeds.
It is commonly recommended that extra moisture is removed from seeds before freezing. My question is … what would be a good rh% and what would be too low?
Here is what I found with search function:
so 25%? 30%? or said 35% ?? Has anyone tested or seen research on this?
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It’s a good question.
Some of the suggestions for other crop seems to suggest a seed moisture content of the seed being key with the relative humidity in storage being dependent on the storage temperature. It would be nice to research a general consensus on the what the RH should be for differing storage scenarios along with what types of desiccants can be used (to avoid over drying).
Storage temperature must be derived from this formula when assessing storage unit effectiveness:
Lower relative humidity means higher allowable storage temperatures, as long as their sum does not exceed a combined value of 100. For example, storage areas with an RH value of 60% need to be cooled to 40˚ F to enhance maximum storage potential. Higher temperatures can be especially damaging if the seed is stored at higher moisture contents. Seed stored with lower moisture contents may tolerate higher temperatures better.
In this paper, it seems to indicate a storage RH below 29%:
https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0960258500001008
In each case from their tests, RH ~30% shows a slight decrease to complete failure in viability depending on the crop.
Some other references:
http://agron-www.agron.iastate.edu/courses/Agron338/Content/Seed%20storage%202013.pdf
https://www.bioversityinternational.org/fileadmin/bioversity/publications/Web_version/243/ch06.htm
http://sbc.ucdavis.edu/About_US/Seed_Biotechnologies/Seed_Storage_Conservation/
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Thank you very much Northern_Loki !!
The camebridge doc stated that extreme drying would not adversly effect viability … so I guess there is no real danger of killing the seeds with over drying. (in case someone else is also thinking about long term storage)
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I still don’t fully understand the ratio of moisture content vs the drying effect of extremely low RH (such as the use of silica desiccant). There must be some minimum MC for the seeds, I’d think. But not feeling confident on what occurs in different scenarios. Please share any insight you’ve gained. I’ll keep looking around, too.
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Just aquired a new 2 cubic foot fridge dedicated to storage so I can have the drawer in my kitchen fridge back 
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I keep them with a tea bag of rice in a mason jar in the fridge,. Recently I had beans pop with an 80 percent rate and the were from the late 70s. I have never had this kind of luck, but low and behold @Instg8ter has a couple growing beautifully.
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First thing I do is ditch the breeder packs. Too many random sizes and poor packages to deal with.
I repackage all seeds in vials of 10 each, packed w/ a bit of cotton to prevent them from moving/rubbing on each other. Then sealed in mylar bags and labelled, and placed into tupperware and stored in the utility room of my basement.
Been doing this system for at least 10 years now and recently popped some old 20 y/o seeds.
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I just found an older mason jar in my stash (about 5 yrs old)
Jar is sealed with large Boveda 62% pak inside at 62% humidity (meter in jar).
Weed still smokes very smooth and nice high, and I found 6 seeds in the weed while cleaning some. Had to try and pop them so I went and stuck them in the wifes herb garden on back Sunny Deck and in 3 days all were up, fastest seeds to even grow for me. LOL
I have stored seeds all ways but dam this was the easiest way.
Mason jar, weed and Boveda pak, store in dark in cool area under 65 degs, very little fluctuation in temp.
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Looking to save some gems and starting to build a nice collection. There is a few I won’t get around to for a few years possible…
Any suggestions?
THANKS!
I store my expanding collection in a black lightproof plastic sack inside a quart canning jar with rice. Key is low temps, no light, and dryness. Others freeze theirs. Do a search on storing seeds on the Overgrow search tool, lots of info about it!
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Hmn in the fridge with silica desiccant or rice.
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Dry and cool in the fridge is best. 
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I store mine in old pill bottles with some paper towel smooshed in. The orange/amber waterproof ones. I also use them to make mini survival kits for camping.
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Inside lab viles with cotton and rubber seals inside waterproof plastic box inside small fridge at 50° f.
Back up inverter generator for the house because I reside somewhere pg@e likes to turn are power off for days at a time when the wind blows 
You’re high, lol
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Always, but what does that have to do with my comment?
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Freezers the way to go.
Your high, was a bit of humour, hence the lol.
But yeah I know yous aint used to that coming out of me.
Thanks! Do you put the pill bottles in the fridge?
I just leave them in the dark where the temperature doesn’t swing too much. A basement would be ideal.
I once stored seeds in a mason jar in a chilly basement for over a decade with no drop in viability.
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