Seeds are designed to wait in the ground until the weather is just right for them to germinate and grow into a healthy plant. Some desert plants can wait for hundreds or even thousands of years for a sudden flash flood to give them the moisture they need to grow. Although not all seeds can stay viable for nearly that long, when stored properly vegetable seeds can last for several years.
Select seeds for long-term storage. If you have a particularly hardy or productive vegetable plant, you may want to save some of its seeds for future planting. You can also store excess vegetable seeds from the store.
Arrange your storage seeds on baking trays or tins. If you are using multiple kinds of seeds, write out paper labels and put one near each group so that you won't confuse them.
Warm the seeds in your oven for an hour at 100 degrees Fahrenheit. This will warm the seeds up enough to drive out much of the moisture without harming the seeds. Dry seeds will keep better than moist ones.
Place each group of seeds in an airtight container such as a glass vial with a stopper or a mason jar. Tape a paper label to each container with the name of the vegetable inside.
Add a desiccant to each storage container. Desiccants suck up any moisture that finds its way into the container, protecting your seeds. You can use several grains of raw white rice or a small silica gel pack. This step is optional, but it will help control moisture.
Leave the containers at room temperature for an hour to allow the seeds to cool slowly, then place them in the freezer. Depending on the vegetable, your seeds may be good for anywhere from a couple of years to decades. Change the desiccant every six months or so.