Saving your own tomato seeds is an enjoyable and economical way to prepare for the future while preserving a part of the past. Here are some simple instructions for saving your own tomato seeds — and some reasons why standard varieties make a better seed source than hybrid strains.
Waiting for the Ripe Time
The gel that surrounds the tomato seed contains chemicals that prevent seed germination. This may seem counterintuitive, but many seeds come equipped with mechanisms that stall germination until the time is right. Without the inhibitors in the gel sack, nothing would prevent a tomato seed from germinating within the fruit while it is still on the parent plant. When a ripe tomato falls off the plant, it sits on the ground and rots away, gel sack and all, and the seeds are left to germinate.
Home Grown Germination
You can replicate this rotting process at home. Cut open a very ripe tomato and squeeze the seeds into a tall jar. Stir the seeds once a day for three to five days. A fungus will form, ferment, bubble and smell absolutely awful (you'll want to keep the jar outside). This fermentation process will kill many seed-borne diseases.
After three to five days, add some fresh water to the jar and shake it vigorously. Conveniently, the fungus and unviable seeds will float to the top, while the good seeds will settle to the bottom of the jar. Pour off the fungus and the water, rinse your seeds and allow them to drip dry. Spread the seeds on a glass or ceramic pan and allow them to dry out completely.
There is an alternate method. Put the seeds with a little bit of water in a sieve and run cool water over them. Swish them around to allow the gel to run out of the sieve. You won't get all of the gel off, but a thorough rinsing should be sufficient. Let the seeds drip dry, then spread them on a paper towel to finish drying out. The seeds will stick to the paper, but it can be easily rolled up to store the seeds in a paper bag.
Storing Seeds
When your seeds are dry, store them in a cool (not cold), dry place away from pests. Be sure to label your seeds with the name of the variety and the date that you saved them. Tomato seeds may remain viable for up to four years, but if you're saving them through the summer, make sure their storage area remains cool and dry, even on hot days.
Don't save seeds from the fruits of hybrid plants unless you have the time and the space for experimentation. F1 hybrid seeds are produced by crossing two genetically different, and usually very inbred, parent plants. Seeds saved from the fruits of hybrid plants generally revert to the undesirable parent varieties — that is, if they germinate at all. Standard, or nonhybrid seeds, will produce plants like their parents, as long as they have not been allowed to cross with similar varieties of the same species. (With tomatoes, the chances of such outcrossing are minimal.)
Why Save
There are a number of other reasons to grow and save seeds from standard varieties. Most hybrid plants are created for the commercial grower, so qualities such as size, quantity of fruit, and tough skin can take precedence over flavor. The fruits of hybrid varieties tend to ripen around the same time — a useful characteristic for the commercial grower — but home gardeners usually want their plants to continue to bear throughout the season. The most important benefit of saving seeds from the best fruits of your best plants is that you will eventually have a strain especially well-suited to your growing area.