Don,
There is a page on the website with the results of a germination test we did 11 years after we packaged the seeds. They had been frozen for two years and then stored on the shelf from 45 to 65 degrees. I planted the seeds in soil in the house and you can see the results from planting 20 seeds. http://downtoearthseeds.com/germination-test-results-for-12-year-old-seed.php The germination was vigorous and we were very pleased. Store your seeds as cool as possible. Germination success also depends on the growing conditions. Lettuce, cabbage, broccoli, etc will not germinate in high temperatures. Conditions must be right for good germination. Our seeds are fresh. We dry them, package them, and then store them at cool temperatures until they are shipped. The stock we have now was received and canned only two weeks ago.
If you have more questions, let us know if we can help.