How to Save Tomato Seeds

Tomato season might be winding down now, but it’s never too late to plan for next year. Learn how to save tomato seeds today, so you’ll have everything you need for a bountiful tomato harvest next summer.

What Tomatoes Can I Save Seed From?

The first thing to understand is what kind of tomato seeds you can save and get reliable results. You’ll need heirloom tomato varieties, also known as open-pollinated varieties. These types of plants are genetically stable and will produce the same type of fruit as their parents, unlike hybrid seeds, which are not genetically stable yet and will not give reliable results.

The great thing about tomato plants is that they self-pollinate and also have a flower structure that makes cross-pollination very unlikely, which means you can grow different varieties next to each other, without any cross-pollination concerns.

How to Save Tomato Seeds

Once your tomatoes are ripe and you pick them, next comes the seed harvesting. One of the best things about tomatoes is that since we eat the ripe fruit (unlike green beans or cucumbers, which are harvested when still immature), we can enjoy the delicious fruit and also save the tomato seeds at the same time.

If you’re saving multiple varieties of tomatoes at the same time, the most challenging part of the process is proper labeling and tracking, so that you don’t mix up the varieties. It’s best to label your containers before you start harvesting the seed.

Once you cut open the fruit, you can squeeze the seeds and juice out, though it helps to pull the seeds out of the cavities with your finger to ensure you get as many as possible.

Should I Ferment Tomato Seeds?

Tomato seeds have a gelatinous coating on them that inhibits germination, so to remove that coating and ensure good germination in the future, they need to be fermented, which will loosen and separate the seeds so they can be isolated and dried well. This mimics the process in nature where a fruit drops to the ground and rots, which accomplishes the same process, though not as thoroughly as our process of saving tomato seeds will.

Put your seeds and juice in a container at room temperature and leave it for about 3 days or until a white mold begins to form on the top. If the tomato did not have much juice and the seeds are not submerged in liquid, add some water to ensure that they don’t dry out during the fermentation process.

After about 3 days, your next step is cleaning the saved tomato seeds, which we do by adding water to separate the good seeds from the non-viable seeds and remaining flesh at the surface. Stir well and let the seeds settle to the bottom, then pour off the gunk at the top. Repeat 2-3 times or until you only have seeds in clear water.

How to Long to Dry Tomato Seeds Before Storing

Finally, pour the seeds into a sieve or screen and let them dry completely. Once dry, put them into a properly marked envelope and store them in a dry, cool, preferably dark place.

Storing Saved Tomato Seeds

Tomato seeds have a long storage life and should last at least 3-5 years with high germination, though we regularly get greater than 50% germination from tomato seeds that are a decade old!

Tomatoes are probably our favorite crop to grow, and there are hundreds of varieties of heirloom tomatoes, so we always recommend that people constantly try new varieties to see what they like and what grows well for them.

Explore Our Collection of 100% Heirloom Tomato Seeds!