On page 975 of that book begins a four-plus page listing of the longevity of seeds. Since I was already collecting and accumulating a seed bank back then, I found this list indispensable. It was the beginning of a life-long fascination with the performance of old seeds. For the last twenty or more years seed here has been stored in the refrigerator (or in much smaller numbers in the freezer). And there are plenty of seed packets, mostly of home grown seed, which have been kept at room temperature for decades.
When I get bored in the middle of winter, I sometimes take out the plastic bags in which the seed packets are stored and go over the packets. The commercial packets, with their vivid colors, are an art form of their own. This always cheers me up. And while I'm enjoying the colorful seed packets, I select a few to test the germination of the seed. This year I selected some seed of Tropaeolum peregrinum, the Canary bird flower, a type of nasturtium. This seed was from a commercial packet offered for sale in 1996, so the seed was at least fourteen years old. I tested three seeds: on January 20, 2011 I soaked the seeds overnight, then packed them in damp tissue paper in a plastic bag. By now, one shows active growth, another is just beginning to show growth, and the third is still dormant (or dead). In the image above you can see these three; there is also a fourth seed of another type of nasturtium from 1981 - this one has so far showed no sign of germination.
Seed packets have become so expensive now that it pays to keep unsown seed from year to year. If you budget the amount you intend to spend on seeds each year, storing unsown seed will allow you to keep to the same budget and still buy different seeds each year.