how long will seeds last?

i found some old seeds i was saving from the early 80's. trying to germinate a few of them, but was wondering how long will seeds last? i have several seeds from several different strains and they are 20 years old.

why don't you just try to germinate them?
20 years looks like a lot of time, but you never know... nature is great!

im new to game but prolly have a lot to do with conditions they were kept in was it dark, was it dry, was it cool, was it peaceful no i dont think that matters im sure success rate down very low if any at all my opinion none the less luck to you my brother.

If they were intact the entire time it's possible, though the oldest seeds I've personally seen germinate were about five years old. I suppose if conditions were right they could last longer.

I have germinated a few seeds that were 30+ years old and the plant was great, but very hard to get any seeds to germ. by hard I mean a lot of time hoping, waiting, and retrying.

I have also found that older seeds seem to have a harder outside seed coat and mine took longer than usual to germ.

But in any case, through back seeds are always great when then grow. Good Luck and don't let anyone tell you it won't work.

They can last a loong time. A very old friend of mines stored seeds he saved from Vietnam as a souvenir when he served there. When he returned to the states, he kept them in a small glass antique jar, which he placed a small piece dry ice in it to remove all the moisture (old Army canning technique I guess). Last year, he decided to grow some of them, half of the seeds didn't make it, but the rest that did gave some authentic,beautiful Vietnamese plants!

i got 5 of them germinating.. just to see if any will sprout. have to wait till next year before i really get a good grow going so ill try them then..