Can I ask how long your seeds last with the above methods?
I store in a cool, dark place, in a sealed tin with those little packet things & keep the seeds in the breeder packaging or paper envelopes. But I rarely get much action from seeds stored over 4 years with this method, and I'd love to be able to do something long term - 20 or 30 years or more. I assume there would be no cheap method to do this, but that would be the grail for me.
Anyway, what's your longest kept but still germinating seeds?