I agree that "dry" is the most important thing for long-term seed storage.
I read about a cheap way to tell whether the inside of a seed jar or box is good and dry. Keep a few strips of newspaper in each jar or bag. If the newspaper is dry enough to crackle when bent and folded, it is quite dry.
If it flops round limply and silently when you finger it, it isn't very dry.
You can also buy humidity-indicating strips for 25 cents, or a one-dollar strip that has different indicating dots for 10%, 30%, 50% and so on.
Seeds "should" be stored well below 30% relative humidity, based on what I read, and I've seen 5%, 8% and "less than 10%" reccomended.
Corey
