To follow up, as veggiecanner said, different seeds have different periods of viability, some being notoriously short-lived: and as kimmsr states, HOW they are stored, being the key word. Freezing, which MANY seed companies do over Winter), is (no doubt) the best method of storage. (Seems to me, I've heard that seeds have been found frozen in glacial ice, thawed, and germinated after MANY years.) A number of times in my life, when inquiring about buying corn seed late in the year, I've been told that they were "already put away in the freezer" (this by a local seed company in my state). I would have preferred not to hear it--makes me wonder how many years some of that seed has been frozen.

Probably not, but don't worry about it. Many of us have posted something on the wrong forum! But I think I have an answer for you. Google "seed shelf life" and see what you can find. Here's what I found and am keeping in my gardening spread-sheet. I think these are minimum years. Some seeds last much longer than the years given if they're stored under optimal conditions. Shelf Life of Seeds Asparagus - 3 years Beans - 3 years Beets - 4 years Broccoli - 3 years Brussels Sprouts - 4 years Cabbage - 4 years Carrots - 3 years Cauliflower - 4 years Celeriac - 3 years Celery - 3 years Chard,Swiss chard - 4 years Chicory - 4 years Chinese Cabbage - 3 years Collards - 5 years Corn - 2 years Corn Salad-(mache) - 5 years Cress - 5 years Cucumbers - 5 years Eggplant - 4 years Endive - 5 years Kale - 4 years Kohlrabi - 3 years Leeks - 2 years Lettuce - 6 years Muskmelon - 5 years Okra - 2 years Onions - 1 year Parsnips - 1 year Peas - 3 years Peppers - 2 years Radishes - 5 years Rutabagas - 4 years Salsify - 1 year Scorzonera - 2 years Sorrel - 4 years Southern Peas - 3 years Spinach - 3 years Squash & Pumpkins - 4 years Tomatoes - 4 years Turnips - 4 years Coriander - 4 years

Nope, Carolyn didn't keep her tomato seeds in film cannisters under her bed for 6 Years. LOL Rather, she initially kept her saved seeds in plastic screw cap vials in 100 place boxes with no special storage at all, just ambient temps. When she'd filled 5 of those boxes in the mid-90's she started saving her seeds just in regular so called invitation envelopes and still does. Switching to first person now. I find that with the ambient temps and humidity where I grow my tomatoes does not require special storage conditions. With seeds 5 yo I expect at least 50% germination and often much more. For seeds about 5-10 yo I'd double sow. For over about 10 yo there are a few tricks to use to try to wake them up. My best effort to date has been waking up 22 yo seed but the documented record is waking up 50 yo seed. Being an SSE member I never bought much seed and have built up a huge seed collection without doing that. But the question is about purchased seed in packets. Just seal them tightly when you're through sowing your seed, put the sealed packets in a sealed container in the fridge and that will be fine. For longer term storage you can freeze the seeds but before you do that you need to get the moisture level of the seeds down to about 5-8 % and you can do that with silica gel. Carolyn, who has never thrown out ONE saved seed since 1989 and darn good thing b'c some varieties disappear and some varieties due to improper seed saving morph into something that doesn't represent the variety as the original one. To date I've grown about 2500 different varieties but didn't save seed from all of them, but still, I've got one heck of a lot of saved seed out there in the back room. LOL

My understanding is most cactus seeds can be viable for several years! I have yet to sow seed, but Im working on getting supplies and everything right now. Here are some links I've bookmarked, hope you find them useful http://www.kadasgarden.com/sowingcactiseed.html http://www.bcss.org.uk/seedraising.php http://cactusnursery.co.uk/seed.htm http://cactiguide.com/forum/viewtopic.php?f=16&t=2144 (lots of cacti seed growing people here)