My seeds are either kept sealed in plastic baggies in my crisper drawer or frozen in my freezer. I'd be interested in hearing what others do and what methods seem to provide the longest viability for tomatoes and other vegetables. I've been able to germinate 25+ year old tomatoes and beans using these methods, but not more than 2 - 3 year old lettuce.

I use a food saver vaccuum sealer and keep in the refrigerator. Very good germination. I believe removing the oxygen and keeping a cool constant temp is the key.

I can tell you what I did for long term storage, but I have not tested if it works or not.

I leave seeds with a desiccant pack for 3 days at room temperature in a small plastic bag. The idea is to remove excess moisture from the seeds. After 3 days, I toss these small bags into larger Ziploc bags with some additional desiccant packs. I do this more in an effort to organize them so when I have to access something, I don't have to keep anything out of the freezer longer than necessary. I put these larger bags into solid plastic containers so the seeds don't get crushed. These then go into my chest freezer. All the desiccant packs should work to keep the moisture in the air in the freezer under control as well.

Maybe overkill and it is possible the desiccants will over-dry the seeds, but I don't think they will since they are in the freezer. I suppose I should have tested it first, but am not that concerned.