Repeat of post to previous swap:

This chart on Joegardener.com is one of the most comprehensive I've seen.

Note that it says the dates are for "optimal" storage conditions but it doesn't say if that means optimal as in their suggested way.

They recommend storing dry seeds in a sealed glass jar with a pack of desiccant, in a refrigerator.

Another site said freezing can further extend longevity but the seeds need to be dried below 8% moisture for this, and not all seeds can tolerate being that dry.

Hope you find this useful. I've decided to only offer seeds I've had for 1 year or less, unless the expected longevity is at least 4 years.

Pat

Pat - Thank you for doing this - I think it's a great idea, and maybe it will be best if we stay with this, as it is.

But what if you make a sticky of a viability chart at the beginning of this thread, that could be modified as folks chime in with viability information? I'd organize it giving precedence to scientific names, with common and synonym names following in second place, which participants could google, with more extensive relevant info following behind in this thread which could be more easily searched if users go to their nga preferences for this site and increase the number of posts per page.

Just a thought. There's a lot of information and experience within and beyond our group, and consideration over how to organize it now as we expand it in the long run might be helpful to Seed-a-Holics in general - especially for those of us with a lot to contribute, but can only tackle this with baby-steps at present.

Just a thought.
karen

oops - When I said: "I'd organize it giving precedence to scientific names...", I did not mean to say "I" would organize the thread, but hopefully the 'thread' could be organized by you or whoever. I'm happy to assist and leave the leadership to you.

Hi Pat - I just edited by previous post

Regarding viability of pelleted seeds, Evelyn in the garden had this to say about petunias, but what she says could also relate to other plants:

"evelyninthegarden said:
Rubi ~ It has been my experience that pelleted seeds need to be used the same year as purchased. I have tried and they just don't last very long. I have very old un-pelleted seeds that have germinated to my amazement. Some weren't even in sealed packets. I hate to waste money (and time) and now that I know, I will just toss them. And if I receive any more pelleted seeds, I will just sow them all, or give the extras to someone who can use them right away. Lesson learned!"

by: evelyninthegarden
Mar 22, 2023 2:26 PM EST

https://garden.org/thread/repl...
- - - - - - -
So, seed viability can vary according to how it was stored before germination is attempted. Years ago my late dh and I saw a lotus blooming in a public aquatic garden outside Washington, DC, and evidently the seed from which it grew had been found by archeologists excavating a buried lake near Beijing, China that might have been dated to about 1500-1700 bp, if I remember correctly.

Karen, I concur about the pelleted seeds. I always disclose pellets in a trade because a year or so is the most you can hope for, though of course there are exceptions.
If I remember correctly, the problem lies in the material used to coat them. Clay based pelleted seeds are less likely to last more than a year or 18 months than other substances, and clay is the most commonly used method. My mind extrapolates that nugget of information into wondering if the clay draws the moisture from the seed. I don't know if that's the case, though.

Alana, I don't know how pelleted clay works on the seed and/or its germination process either, and also wonder about the iffy role of moisture in all this too.

But I have also read that some pelleted seeds do not respond well to the winter-sowing technique anyway.

So, as expensive as some pelleted seeds seem to be, to future experimenters:

- - - - - - - - Choose your experiments / battles wisely - - - - - - - - - -

karen

@Bluespiral I had heard the same about pelleted petunias. I sowed some 2 year old pelleted seeds last year and the germination was lower but a good amount still germinated. I have some 3 year old pelleted petunias that I'll be sowing and I'll update how germination goes with them. A lot of my pelleted petunias from GeoSeed and Harris have 500 seeds so I just can't sow them all in 1 year.

I did not know that about the pelleted seeds. I would have thought the complete opposite that the pelleted substance would protect them.

@susiesjoy Thank you for the acorn!

@bluespiral
Hi Karen, Thanks for the encouragement! I was actually toying with the idea of making a seed longevity chart sometime in a more permanent location. Did you make this a sticky? I don't know how to do it. I thought it might belong somewhere that all seed swaps and Seed-a-Holics could find it easily.

I have bookmarks on various websites with seed longevity info. And more in various books. I have some of the "scientific" books on seed germination and seed storage. (In grad school I taught Plant Propagation labs as a TA). So I was thinking of compiling more when I have time... but somehow I never get any more hours than usual. 😄

Including information from growers would be great too! Seed sellers generally say somewhere that pelleted seeds have reduced longevity and often recommend sowing them year of harvest. (That's one thing the swaps are terrific for - sharing excesses of those seeds asap!) I have not yet seen published information on longevity of specific kinds of *pelleted* seeds (nor have I formally searched yet).

So collecting experiences with those, as reported here on NGA or elsewhere, could be a real contribution, in addition to the rest!

Let's do it! As soon as we figure out the "mechanics". I love your enthusiasm and willingness to work on this Karen! 😃 If you have the time to run with it right away, please do! I can funnel information into it as I find it. And we can hope lots of others will too.

Pat

Edit: PS I like all your ideas for information to include. You already have a "grand vision " of what could be created, in baby steps if needed, but there's plenty of information available for a launch. There will always be new information coming along to add. It will never be done, so the only thing we can do is make a start.👍🏻

When I was contemplating potential additions to the longevity chart I also considered trying to include somewhere anecdotal experiences with greater longevity.

Such as, my experience with a 10 year old packet of Burpee seed rack Fourth of July tomatoes which germinated at nearly 100% I probably have the exact number recorded back when it happened. I planted them because I had seen other reports of tomato seed longevity range of 5-10 years. So I thought I might salvage a few plants. Surprise! I would compact that to something shorter:

Tomato, 10 years, 90+%, Burpee Fourth of July, original paper packet, dry, sealed plastic box with similar packets of other tomatoes, indoors, climate controlled room (heat, AC), av. 72°F, Ohio.

Maybe some people would be interested enough to do small experiments on longevity and report results.

Pat

Alrighty - everybody's enthusiasm makes me feel free to dive in - and I will, but only "inch by inch" (Pete Seeger, folk song) - speaking for my present situation.

One source I very much respect is the notes on germination in the ethnobotanic seed catalog: www.jlhudsonseeds.net , that takes the subject of seeds into different eras of culture and history - I think they sell germinating supplies including giberrellic (sp?) acid & liquid smoke sold for barbecues? - evidently Angelonia originated on Carribean islands where wildfires were a natural part of their habitat) and historic/scientific printed references.

And then there's NASA's Astronomy Picture of the Day - https://apod.nasa.gov/apod/ast... . I once followed the links for a picture of Hurricane Irene? and those links took me to math about how that hurricane's spiral pattern (logorithmic spiral) - was the same pattern that the seed disk flowers in the center of a sunflower are arranged. - https://www.google.com/search?...

Well, that pattern is also explicated in the Greek Parthenon and I just mention this in case someone else's curiosity might enjoy the chase

But botanic/germination experiments have also been conducted in a space station, which this Astronomy Picture of the Day's links have led to in the past.

I can't chase this down right now - but just in case somone else might like to see if there's something there to add to this thread?