By Sandy Feather ©2009
Penn State Extension
Store your vegetable seed in airtight jars or containers in the refrigerator.
Those silica gel packs that are shipped with shoes and electronic equipment can be placed in the container to help keep the seeds dry. Be sure to mark the seed containers with the variety and the date saved. Depending on the vegetable crop, seed will remain viable from one to five years. You can check the germination by sprouting the seeds between moist paper towels.
If germination is low (say one out of ten seeds), discard the old seed and buy fresh seed. You may be able to plant enough of the old seed to get the desired number of plants.
Vegetable Seed Viability – The number of years vegetable seed can be stored
Source: Penn State Master Gardener Handbook
By: Sandy Feather ©2014
Penn State Extension
Be sure the tomatoes you want to save seed from are open-pollinated varieties, rather than hybrids. Seed saved from hybrids may produce plants and fruit that are not the same as the parent plant, and you may be disappointed in the quality of the fruit. Saving seed from tomatoes is not just a matter of harvesting the seeds and letting them dry, but it is not difficult.
Extracting Tomato Seeds
The gel inside the tomato that holds the seeds contains growth inhibitors that keep them from germinating inside the fruit. This must be fermented off before storing the seed for winter.
Simply harvest fruit from the desired plants when it is ripe. Cut the fruit and squeeze the pulp into a container. Add a little water and allow it to stand at room temperature for two to four days. Stir the pulp occasionally. When the seeds settle out, pour off the liquid. Spread the seeds on a paper towel in a single layer and allow them to dry thoroughly.
How to Overwinter Tomato Seeds
It is important that seeds are stored under cool, dry conditions. Place the seeds in an envelope marked with the variety. Then place the envelopes in an airtight container.
The little packets of silica gel that are packed with electronic equipment, shoes, etc. can be saved and placed in the container with the seed packages to absorb any excess moisture. Store the container(s) in your refrigerator until you are ready to plant the seeds.