I have some cucumber seeds that my friend saved 10 years ago. I tested the germination rate and got 90%! A quick way to check the germination rate of seeds left over from previous years is to place 10 seeds on a damp paper towel, fold the towel over, and place it in a worm place. If 9 seeds sprout, you have a 90% germination rate, 8 seeds-80%, etc. Very quick, very simple.