How to Save Tomato Seeds

Fall is a time for many things: cooler temperatures, shifting light, being bombarded with pumpkin spice everything, and saving seeds. Particularly tomato seeds.

I grow several types of heirloom tomatoes each year. Some are new-to-me varieties that I started from purchased seeds, some are from starts that I picked up from a nursery, and some are tried-and-true varieties from saved seeds. It is relatively inexpensive to buy seeds, at only a few bucks a package, but that can add up fast if you’re trying many varieties. I also like saving my tomato seeds because it makes me feel even more connected to my plants, knowing that I not only grew this tomato, but also that I grew and saved seeds from its parent/grandparent/great grandparent/etc. Plus, its totally free, and a fun science experiment.

This year, I’m saving seeds from Heinz 2653, a red Roma type tomato that I use for sauce, canning whole, and salsas. My mom originally bought these seeds from Territorial several years ago, and gave me some of the fruit. I saved seeds from them and have been growing them for at least 3 years. I’m also saving seeds of a gorgeous slicing heirloom that I bought as a start about 5 years ago. It was labeled as Striped German, and from internet searches, I believe these may have been the original seeds. However, mine are much more red and striped than seed catalogue shows. It could have been a different plant, or it could be natural variation from saving generation after generation.

Saving tomato seeds are easy, but they do take a bit more prep than just dry and store like beans. Keep reading for all you need to know to save your own tomato seeds!

The first step is to determine if your tomato seeds CAN be saved.

If your tomato is a hybrid, the plant coming from your saved seed won’t be true to what the parent was like. This is true to any plant, flower or vegetable. Hybrids are much different than genetically modified plants (GMOs). A hybrid is created by intentionally cross-pollinate two different varieties. Cross-pollination is a natural process that occurs within members of the same species, but hybridization is pollination that is carefully controlled. The process of developing a hybrid typically requires many years, and usually not done by home gardeners. Saving and growing seeds from a hybrid could be a fun experiment, but you won’t likely won’t get the same type of fruit.

To know if your tomato is a subject for seed saving, there isn’t a way to tell from the plant itself, so check the seed package or the plant tag. If it has the words ‘hybrid’ or F1 listed in the name or description, it’s a hybrid. If its described as open pollinated, OP, or heirloom, you’re good to go.

Next step is to collect your tomato seeds.

You’ll want to save seeds from plants that were healthy, and obviously, from varieties that you enjoy! If there was a particular plant that held up to drought stress or resisted blossom end rot (a nemesis in my garden) or produced particularly delicious fruit, those are good characteristics to encourage and are good candidates for saving. Pick your tomatoes that are the best that you have- leave the cracked or misshaped ones for sauce. I like to harvest several and from a few different plants to encourage genetic diversity.

Before we can dry and store, we need to pretreat the seeds. There are two ways of doing this. First, you let the tomato rot. You can set this outside in a protected area or even on your counter. Then, you would gather the seeds. The second, which is the method I use, is to collect the seeds and let them ferment in a jar of water. I recommend this method- less ick and less fruit flies.

To collect the seeds, cut the tomato open and squeeze out the seeds and pulp into a jar. Cover with a bit of water, and let ferment. Stir the seeds and waters a few times a day. Mine live on the windowsill above my kitchen sink. After about 4 days, the fermentation process is done. You will likely have a layer of mold on the top of your jar, and some seeds may have also floated to the top. This is normal.

Pour the water and any floating seeds (those are non-viable) away, then rise the remainder with fresh water. Spread over a tea or paper towel, and let dry for a week or two.

Once dry, they are ready for storage!

Label and store your seeds.

I like to store my seeds in simple paper envelopes. I use a box of cheap white letter sized envelopes, and seal them. Then, I cut the top off one end, add my seeds, then fold the top over and tape closed.

Sealed glass jars or plastic bags can also work. Reused spice jars or baby food jars a great way to store seeds. Don’t forget to label the variety, the date collected, and any other notes you want. Tomato seeds are viable for 4 years, but I usually save some each year. Keep in a dry, dark place and you’re good to go!

I’d love to know, are you saving any tomato seeds? What varieties did great for you this year? 

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