You say you saved some of those garden seed from last year.
Lets take it in order.
Seed shelf life varies according to the vegetable. For example seeds that have a one year shelf life are Onions, Parsnip, and sweet corn. Those with a two year shelf life are, Okra and Soybeans. For a three year shelf life you have Asparagus, Beans, Carrots, and Peas. Now for four years you can save Beets, Mustard, Pepper, Pumpkin, and tomato.