Year Old Seed Works
I was happy to see some zucchini seeds I had in the garage from last year sprouted. That saves me from buying new seed for them this year as I usually do. Don't we all?
I know some seeds, onions for example, go bad real quick. I wasn't sure about squash and checking the viability list in Mel Bartholomew's Square Foot Gardening didn't help. Maybe I missed it, but the list didn't include squash. I should have just gone online as there are a number of different lists. Here's one so you can check to see if your seeds from last year- or even older- might still be good.
I tried broccoli seed earlier on. They sprouted, too, but I left them out overnight and the snails ate them.