I have some leftover seeds from 1 year ago. The date on the package is over two years old. Are the seeds worth saving or should I just pitch them?
With some notable exceptions, good seed viability is generally 2-3 years. Germination rates will drop off after that but they are still worth sowing to see what comes - it is better than just throwing them out!
How and where they've been stored has a great deal to do with how good the seeds are. Seeds are not inert, but are living embryos in a state of suspended animation, so to speak. The longer you save them, the more seedling vigor you might be sacrificing.
But if the seeds were stored in optimum conditions for their type, you'll likely have pretty good germination results.