Old seed germination

I know we've touched a bit on this before in other areas, but with the unreliability of online "expert" sources of conflicting/contradictory/regurgitated information from site to site, I was hoping this thread could be a place to give actual examples of vegetable seed viability time.  I know the storage conditions matter greatly, so if you would, please share with us your old seed success or failure stories along with the storage methods used, so that we can all have a greater understanding of expectations for shelf-life.

For example, Sweet Corn seed is typically 1-2 years viable according to accepted standards.  I had several varieties of old sweet corn seed that weren't stored very well; it ranged from 4-12 years old.  

For the smaller amounts of seed, I tried the wet paper towel method to gauge germination rate.  Out of all the varieties, only a half dozen seeds germinated & survived mold to the point of healthy seedlings.  I used those to fill the "holes" in my corn rows, theoretically adding seed longevity & fungus resistance to my landrace/mix.  Surprisingly, the 4 year old seed failed, so it was older seeds that survived.  I've since learned about better ways to keep seeds happy, and will be applying those lessons in future long-term seed saving trials.

I have heard accounts of sweet corn lasting 10 years in a freezer.  The grower simply took out enough each year to plant, & put the remaining seed back in the freezer.  I've not tried this, but may soon move to freezer storage in mylar bags as my seed collection grows.

I recently tried 4 packets of alliums which also have a 1-2 year shelf life.  1 chives, & 3 different bunching (green) onions.  These were from around 2008.  About 100 seeds with Zero germination.  No surprise really, but no need to keep seeds that won't grow.  

I've found my results to be all over the place, I'm afraid. This year I just literally threw about 100 daikon seeds I bought a few years ago in the garden expecting nothing- they never took before. I have picked about 50 kg of daikon so far and they're still going.
A lot of it seems to be the situation at the time (and I consider the phase of moon in planting my seeds)-- some years not one works (that was my okra last year, not a blessed one came up, 5 different varieties from different companies and even different countries, it seems someone upstairs really didn't want me to have okra), and some years even the things you didn't expect do really well. I don't calculate my germination, really, but if it's not a new pack from this year I really don't expect much, I always plant twice as much as I need and if it all comes up I have neighbors who appreciate starts.

(I started thinking about moon phase one year when I planted beans from a trusted source and not one came up. I found the moon phase calculator and experimented, planting one bed on an ideal day and another on a do-not-plant day, and the results were astonishing. I didn't expect to believe in "this stuff" but you bet now I check the calendar to make sure it's at least not a do-not-plant day before I start seeds.)

Wanted to add: I live abroad and collect seeds from all over the place: I am a seed-collecting pack rat. I keep them FOREVER.
Very Important Seeds I keep in the fridge (when i come back from a trip abroad with fresh seeds for the next planting season), but my space is really limited so most of my seeds are kept in a metal tin out on my porch in a cabinet (so not totally temperature stable, but still variable). Most are not kept in the fridge.
I do often get corn germination from far beyond 1-2 years. The one seed I can count on to be ornery and not germinate is swiss chard, those I have to buy every year. Other than that, I just never know.

Gibberellic acid - GA3 works well for bringing back old seed.

It's rather expensive to purchase, and usually only available in large amounts.


I'd only use it if you have something that you can't find anywhere anymore - or if you got seeds from another country imported over.