Yes, use them if you have stored them in a dry place. I grow a lot of my garden with seeds that were not sold for the current year. Lettuce, onions, and chives would be the most likely to have poor germination after a year or two. Most of the others will be viable much longer. I've grown even lettuce and onions from seeds purchased for the previous year without significant germination problems but have seen a drop in viability if I keep those two kinds of seed longer than that.

I definitely don't buy new seeds every year!

I think the oldest I planted this year were from 2006, but I had great results, and I have planted older seeds in the past. I planted heavily, because I feared poor germination, but I sort of wish I hadn't, because now I'm overrun...yesterday I counted 55 pepper plants, and I can't imagine I'll be growing more than 10. The tomatoes were planted more recently, and are only now starting to show true leaves, and I don't even want to think how many extras I have of those.

I find that the length of time that seeds will keep can vary a lot, and doesn't always have any relation to how long the seeds are "supposed" to keep. Seeds of the onion family, for instance, are known to only keep for a very short amount of time, but my 2006 leek seeds came up like crazy. I had several pepper varieties from that same year, and most of them had great germination rates, though the yellow bells didn't come up at all (though these may have been a lower quality of seed to begin with).

Also keep in mind that generally speaking, it's not that seeds suddenly stop germinating. The germination rates will taper off over time, with most of them germinating for fresh seed, and almost none germinating for really old seed, and everywhere in between during the intervening years. You can compensate by planting more heavily.

I completely understand your desire not to waste precious time on possible duds...but I'd say to get them planted as soon as you can (on the early end of the appropriate range), sow a bit heavily, and be prepared to either thing them or run out to the store to get a new packet of seeds if something doesn't come up. Take into account things like how long the appropriate planting season is (how bad would it be if you discovered your seeds were duds, and you had a 2-week delay because you had to buy new seeds at the store after they didn't come up?), how hard it would be to take an alternative option (could you run out to the garden store and buy plants this year if you had to?), and other things, like "how many varieties do you really need?"

Another option is to hedge your bets, and get a few new seed packets of different varieties of the same thing, and plant some old, some new. For instance, I had multiple varieties of pepper and tomato seeds this year, of varying ages. I planted some of each type, and hoped for the best, knowing that I would certainly get some peppers and tomatoes. If one variety didn't make it (which happened for the peppers), I would only be sacrificing variety, and I wouldn't be in danger of "no tomatoes or peppers at all." Of course, if you have your heart set on a particular variety, and especially if that variety isn't available in local stores, the stakes are a lot higher.

I store my seeds in a ziploc bag in the fridge, though some people use the freezer, with even better results. There was someone here just a couple of years ago who had just (successfully) planted seeds from 1977.

You can check the viability of the seeds by placing a few on damp paper towels inside a plastic baggie. I presprout many of my seeds this way. Then I know I'll have a certain number of a particular veggie.
I store my seeds in a plastic shoe box in a dark cupboard with a couple silica packets.
I usually have pretty good germination with 2-3 yr. seeds. I did have to buy new parsley and eggplant seeds this year.
Keski

I presprout my seed the same way Keski does. It works very well for a small(ish) garden. I like knowing exactly what I have, & the seed tends to sprout quickly (esp. if you put the baggie on a warm surface like the top of the fridge or water heater). Plus, I am usually sprouting some older seed leftover from previous years. This year it was only 2 year old seed, but 2 years ago I sprouted some seed from the late 90's. I have always kept my seed in a plastic tub in the house, but just this year started keeping it in a ziploc bag in the fridge, based on advice from this forum.
For herbs, I've been having better luck putting the seed directly on damp seed starting mix in a small pot & then wrapping the pot in a plastic bag. I usually use a Popsicle stick for a name tag, & that helps hold the bag up from the pot. I put the pot in a south facing window. Then, when there are sprouts, I can prick them out.
I would probably try everything I was interested in. It shouldn't take that long to figure out what will sprout. I have done all of the veggies you've mentioned in paper towels. In some cases, with really old seed, they got stinky right away. I would just toss that paper towel (each paper towel marked with the variety in permanent ink on the edge). 2-3 years is not that old, though.
Good luck! Let us know how it works out.

I tend to use seeds until they are gone. And I don't do anything particular to store them except keep them indoors. It's like leira said, they don't tend to suddenly stop being viable, they just have fewer germinate over the years. I have partial packs of all the veggies you list that are more than two years old, and I still plant from them. I do buy fresh seed every year also, but that's just the nature of this little addiction called "gardening".

Actually, sunnibel7 is right, I misspoke. I absolutely do buy new seeds every year...just not for the purpose of replacing the ones I already have!

Thanks for the good advice. I like the idea of buying a different variety to try as well as using existing seeds. With the exception of tomatoes, I tend to buy the same varieties every year.

For those of you who do a germination test...do you end up potting up the sprouted seeds?

I buy seeds every year, but only to replace old ones I run out of, or am almost out of, or to try another variety on top of what I have or just to buy something I don't have.

You certainly can pot up the sprouted seeds from a germination test. The sooner the better in most cases to avoid damage to the roots. I personally will pot up ones I usually grow as transplants. If it is something I have lots of seed of and would rather direct sow, I'll toss the test ones into the compost.

Seeds in ziploc bags in the freezer last forever. My oldest ones are Brandywine toms, Romaine lettuce and January King cabbage, all from 2000 or 2001. Remarkably, I have perfectly viable parsnip seeds from 2006. They should last one year.

I keep all of my seeds in a dry and cool place, and the germination rates remain quite good year to year. The only seeds that I purchase fresh every season are carrots.

Here is a link that might be useful: My seeds and garden

I didn't start much from seed this year cause I was on vacation and didn't want to burden my daughter with taking care of the "babies"
When I do start from seed I'm very lucky to have a seed bank that meets 1x per month and I can get what I need.
There are only 2 of us, so I don't need more than 5-6 tomato plants, but I don't want to buy a package for each type of tomato and I like to try a couple of new ones each year, so I go to the seed bank and get local GMO free seed!
Some, that I'm planting quite often, I buy from the big box store (I don't want to hog all of the seeds at the bank!)
This year I'm doing starts from a non-profit/organic sale that has fantastic, healthy plants for dirt cheap! You have to get there really early in the morning to get what you want! Nancy

I'm too cheap to throw away seeds every year. :-)

I, like a previous poster, keep my seeds in baggies, in a cigar box, in the freezer.

http://agrowingcuriousity.blogspot.com/

seed's viability with time differs with the various plant families, and as others have said, depends a lot of storage conditions. When I have seeded before, we doubled the amount of seeds in each cell for every year after the seed was bought. If more than 1 seed germinated, we just thinned them or separated them.

No. I don't replace seeds every year. I've had seeds from about 1995 that sprouted this year. If you're in doubt, overplant. That way, some will probably sprout, and you may be surprised and have a bumper crop.

Exceptions would be carrots, onions, and maybe lettuce. I've had lettuce surprise me, though, and be viable years after it was supposed to have expired. But then, I keep my seeds in the fridge.

An update:
I am pre-sprouting a few old seeds and just noticed germination from a sunflower seed! I'm pretty sure they are at least twelve years old. Now I'm curious to see what other "life" is in that old seed box!

I'd recommend saving as much seed from your own crops as possible. Can do this with quite a few varieties. I'd also endorse the wet paper method of checking germination... just did it with parsnips and nothing from seeds from one packet 2yr old packet whereas all the seeds from another variety the same age germinated.

I've included below a link to a post on saving your own seed. Hope it helps, John

Here is a link that might be useful: Allotment Heaven : Saving your own vegetable seeds

You can pot up the seeds you sprout, or plant them directly out if you want to. I have pre-sprouted beans (& plenty of other things) & then put them out directly into the bed. They come up a lot quicker that way, & there are times I don't want to spend the time or money on potting up. I tend to be an impatient gardener (or maybe it is just that there is a lot of other stuff going on in my life) & even when I pot things up, I tend to put them outside right away because I'm not good at hardening them off later! I have always gardened in warmer zones, though, so I haven't had to worry too much about cold - more about drying out too quickly. This year I've had to pull my flats in from time to time because of thunderstorms, though.