Have you started your own tomato plants from seed yet? Saving Tomato Seeds for next year’s garden is a little bit more work than for other vegetables, but the reward is very much worth the effort.
When you save your own seeds you get to choose the tomatoes from your garden which performed the best, were the best tasting, largest, or any number of other characteristics which appeal to you. That’s the beauty of seed saving from your own garden – you can select for the traits you want to grow by selecting the fruit to harvest with those same traits.
Plus, I think it makes me a better gardener, because it forces me to really pay attention to the plants – straight through to the tail end of the growing season. I still want those plants to be just as beautiful as the ones from early summer if I intend to harvest seeds in the fall.
There are a few different methods to save seeds. This method, the fermentation method – is the traditional way that gardeners have saved seeds for generations. I also like the paper towel method – I have actually had excellent germination rates recently by not fermenting the seeds. But fermentation is still a tried and true process, and so definitely worth understanding.
Fermentation Method
There are a couple of things to know before you jump in. Saving tomato seeds from homegrown tomatoes using the fermentation method is just a little trickier than saving squash or pumpkin seeds. But it isn’t hard. Just a little knowledge goes a long way 🙂 Read this next if you are looking to start your tomato plants from seed.
You know the little slimy bit that surrounds the seeds of the tomatoes? That actually contains a growth inhibitor which can be removed to better allow the seed to sprout. Why is there a growth inhibitor inside the tomato? Purportedly it prevents the seed from sprouting while still inside the tomato. I’ve seen seeds sprouting inside lemons and pumpkins, and I do not want that inside a tomato.
Here’s the process for Saving Tomato Seeds for next year’s garden using the fermentation method:
Choosing the Tomato
First, when saving seeds, always choose a large and healthy fruit. You don’t want to choose one that has a deformity or never got very big – those genetic traits can actually be passed down through the seed. This is true for any plant – including both vegetables and flowers.
Also, heirloom tomatoes will generally stay true to the parent tomato plant that you got the seeds from. Hybrid tomatoes will not. What does that mean in plain English? Well, tomatoes you’ve bought from the supermarket, when saved and grown from seeds… the next generation may not turn out like the tomato you bought in the store. However, tomatoes you grew in your garden such as beefsteak, brandywine, or cherokee will be very much like the parent plant. So these are the varieties you want to save seeds from.
Slice the tomato in half to expose the seed cavity. Inspect the seeds to ensure they are large and healthy. You should be able to see the gel-sack around each seed. Scoop the seeds out into a clean clear glass jar. It is OK if there is a bit of flesh still surrounding the seed.
Fermentation Process
In order to remove that gel covering which contains the growth inhibitor, the theory is that the tomato seed needs to actually rot and ferment. In nature, this happens naturally when the fruit falls from the plant and starts to rot in the soil. We can take a few steps indoors to replicate this process.
Your seeds should now be in the clear glass jar. I really like the clear glass because not only can you see the seeds and the fermentation process, but also you can cover the jar with a lid to prevent both smells and fruit flies. Depending upon the tomato variety and the amount of juice, your seeds will likely be floating in liquid from the tomato. If they are not, add a little bit of water to help separate the seeds from the pulp. You want there to still be lots of room between the top of the water line and the rim of the jar.
Keep the jar of seeds, pulp and water on a windowsill or other warm location. The seeds need to remain there in the sun for just 48 hours before they start to activate. When the process is completed, bubbles will start to rise from the mixture and it may start to grow mold, however this is not guaranteed.
If you look carefully, you will also notice that the seeds should have settled to the bottom of the jar, but the thicker pulp and mold will remain floating on the top. This is the perfect time to remove the seeds.
Removing, Drying and Saving the Seeds
Very gently pour off the floaters from the jar, being very careful to keep the sunken seeds inside the jar. If there is a lot of pulp, you may wish to use a spoon for this. Next, add some fresh water to the sunken seeds in the jar. Put the lid on the jar and shake vigorously.
Allow your seeds to settle back to the bottom of the jar a second time. Any seeds which float will not sprout and you can dispose. All of the seeds on the bottom of the jar are your good seeds. Pour out all of the water and rinse the good seeds. You can use a very fine strainer for this process. or, you can just add fresh water to the seeds and stir. Try to remove any bit of pulp which may still be remaining.
Now the seeds need to be dried. You can use a paper plate or bowl; preferably something without a waxy surface. Set the plate in a warm dry spot such as a sunny windowsill. Allow the seeds to dry completely. Every few days, shake the seeds so that they do not stick to the plate and can dry evenly.
Saving the Tomato Seeds
Once the seeds are completely dry, you can store them in an envelope. I prefer paper as that will absorb any excess moisture still in the seed. Make sure to label the envelope with the variety and year. Tomato seeds should last 5-6 years.
I hope this encourages you to try saving your tomato seeds for next year’s garden from your own tomatoes this year! Let me know if you will be saving tomato seeds or if you are already preparing tomato seeds for planting in the comments below!
Here are some other guides for planting and growing tomatoes:
