As the tomato bounty roles in, there are dozens of potential future tomatoes tucked into each delicious fruit. Often tomato seeds are eaten or scooped out and composted when they could be saved for future growing seasons. This is an opportunity to save the varieties you love, practice food sovereignty and to save money on seed.
When selecting tomatoes to save seed, there are four important questions to consider:
- Was the tomato plant an open pollinated or hybrid seed variety? Varieties that are open pollinated should come “true to type” meaning with correct isolation strategies (more on that below), the seed you saved when grown out, the plants and fruit will be very similar to the one you collected the seed from. Hybrid seed, which involves crossing two different varieties to get specific, desired traits, won’t come true to type. It will still grow a healthy tomato, but won’t look like what you grew before.
- Was the tomato plant mixed in with lots of other varieties of tomato plants? Tomatoes don’t require large distances of isolation to prevent cross pollination because they are self-fertile (6 m to be safe). However, if you have a bunch of different varieties growing side-by-side you may see some crossing, which means you’ve created an accidental hybrid! Again, still will grow a fine tomato plant, but it won’t necessarily look, taste, or perform the same. The way to plan for this in the future is to grow only one variety if you are tight on space or space out plants accordingly. Remember, you can always trade fruit and seed with your neighbours!
- Was the tomato plant healthy? Be cautious about saving seed from plants that show visible disease. This is because certain diseases can actually infect the seed and potentially make the next generation sick. However, with some diseases like late blight, the concern about it being seed born is not so worrisome because the disease is so prevalent in the environment and the fermentation process of cleaning the seed helps prevent disease (more on fermenting tomato seeds soon!) A good rule of thumb: save seed from the healthiest looking plants, save soon (tomatoes tend to go downhill as they get closer to frost!), and don’t save from fruit with visible disease markings on the fruit itself.
- Was the fruit ripe? Harvest the most tender, ripe fruit possible and save from that. This is because you want the seed to be fully formed. A good rule of thumb. However, you can harvest a little under ripe if need be. Just make sure to allow fruit to fully ripen indoors before taking seed.
After considering these questions, grab your fruits and let’s ferment!
Tomato seed is encased in a jelly-like coating, which protects the seed and prevents early germination so the seed does not germinate too early. This coating must be removed in order to save and store the seed. A light fermentation process does the trick!
Garden Gate Magazine “How to Save Tomato Seeds”
Step 1
Cut open tomato in half or quarters.
Squeeze seeds into jar (don’t worry about extra goo).
Make sure jar is labeled if saving more than one variety of tomato (name, harvest date).
Step 2
Add a small amount of water.
Pop on lid (not necessary, but keeps fruit flies out).
Shake or stir.
Place in a warm location.
Step 3
Leave 1-2 days. You will begin to notice seed and fruit debris separating.
Step 4
On day 2 pour off water, debris, and floating seed. Seed that sinks is viable. Seed that floats was not fully formed.
If there are a lot of seeds still floating, simply strain, leave all the seeds for now.
Add more water and shake or stir.
Step 5
On day 3 or 4, repeat, especially if the water is still very murky.
Later that day, drain off water and debris.
Strain and rinse viable seed.
Step 6
Lay cleaned seed on a plate or screen. Avoid laying on paper plates or towels (the seed sticks).
Allow to fully dry in an airy place for 1-3 days.
Make sure drying plate/screen is labeled (see step 1).
Step 7
Store in glass or plastic (preferable) or paper bag (not ideal but works). Store in a cool, dry place.
Make sure labeled.
Tomato seed is viable for up to 5 years.
Step 8
Make sure to share your seed bounty with neighbors, friends and your local seed library!
Special notes:
- Seed should not be fermented for more than 3-4 days. Longer fermentation affects seed and future seedling viability.
- A little bit of mold and stink in the fermentation process is normal.
