Homegrown tomatoes are the best tasting tomatoes on earth. We can all agree on that!
I know it’s true because tomatoes are the most popular vegetable grown in home gardens. Gardeners love them because they’re pretty easy to grow, make a lot of fruit, and they taste so much better than what you can get at the store.
It’s hard to narrow down your favorite tomato varieties, so when you find some you like, you’ll want to keep your own stash of seed to plant from year to year.
Plus, did you know that if you save seeds from tomatoes from year to year, your tomato plants will adapt to your particular environment and become even healthier and more productive over time?
I used to think that saving seeds from tomatoes was, honestly, just too complicated. But since I’ve learned more about it, I realize that it’s not any big deal.
So if you love your homegrown tomatoes, read on to learn all you ever wanted to know about tomato seed saving.
There are actually 3 ways to save tomato seeds.
First I’ll talk about fermenting the seeds because that’s the ideal method. Then I’ll mention how to save tomato seeds without fermenting because it’s so dang easy!
Now I promise I’m going to tell you how to save seeds, but first I want to talk about which tomatoes to choose to save seed from.
Harvest tomato seed from the healthiest plant in your garden.
Watch your tomato plants as they grow in those first few weeks. Do any stand out to you? Is one more vigorous than the others? Which is the first one to make fruit?
When you see a tomato variety that thrives in your garden, take note to save seed from it.
You might even choose the first ripe tomato on that plant for saving seed.
Now I know that is just torture, but there are a couple of good reasons for saving that first tomato.
- You’re selecting the earliest tomato to ripen.
- It’s pretty much guaranteed to give you pure – not cross pollinated – seeds.
- You won’t miss your chance because either you forget to save the seeds later or some disaster ruins your crop.
The other thing we have to talk about is choosing to save seed from heirloom tomatoes. An heirloom tomato is an open-pollinated (not hybrid) tomato variety.
Heirloom tomatoes are the best choice for saving tomato seed because they will reliably grow the tomato you love every year.
You can save hybrid tomato seeds, too, though.
Saved hybrid tomato seeds are like a box of chocolates. You never know what you’re gonna get.
Okay, that’s goofy, but it’s actually the best way to describe it. Because hybrids have a mixture of genes from two different tomato parents, when you grow out the seeds the tomato plants all get a different set of genes.
So you may get some things you love, or you might hate them. Only you can decide if it’s worth the risk. 🙂
Now that you know which tomatoes you’re going to choose for seed saving, you’re ready to learn how to save tomato seed from your garden.
How to save tomato seeds by fermenting
3 easy steps to fermenting tomato seeds:
Step 1: How to seed a tomato
Slice the tomato along the bottom to expose the seed cavities.
Squeeze the seeds into a cup. Any cup will do. You can mix tomato seeds from the same plant, but use a different cup for each different type of tomato.
Plastic cups are convenient because you can write the variety name right on them, and they can be washed and reused.
Step 2: How to ferment tomato seeds
If the tomato wasn’t particularly juicy, add a little water to the seeds and juice in the cup. You need just enough liquid to cover the seeds and meat in the cup.
Cover them with a towel, and set them where you can keep an eye on them so they don’t dry out.
Let them ferment for 3 to 7 days. They will get a little mold growing on the top. That’s okay.
Step 3: How to dry tomato seeds
First, rinse them by adding more water and carefully pouring off the mold and excess water.
Lay them out to dry on a paper towel. They’ll need another week to dry out.
Gather the seeds into a labeled envelope
Is it possible to save tomato seeds without fermenting?
Yes! Saving tomato seeds without fermenting is absolutely doable, and if you’re short on time this is the way to go.
- slice open your tomato and squeeze to push out the seeds while you smear it across a paper towel.
- let them dry on the paper towel for a week or so.
Fermenting is the preferred method for saving tomato seeds.
While saving tomato seeds on a paper towel is very quick and easy to do, the fermentation process is a good practice for getting cleaner seeds.
The fermenting removes the growth inhibiting substances within the tomato gel and can decrease the chances of passing on any bacterial or fungal disease to the next generation to make sure you’re getting the best tomato seeds.
Fermented tomato seeds yield higher germination rates and will last longer in storage.
But there is a way to ferment tomato seeds that is even easier than the paper towel method. Which brings me to…
The third way to save tomato seeds
Just leave a few tomatoes to rot in your garden, and the fermentation process will occur naturally outdoors. You totally skip the step of harvesting tomato seeds, but in the spring, you’ll still have some tomato plants sprouting.
You won’t have control over when they come up or be able to plant them deep for good root structure. And there’s always a chance they’ll pop up too early and get killed by frost.
So it’s not the best way of preserving tomato seeds for planting. And I don’t recommend relying on this method of saving tomato seeds, but it does work.
We had a cherry tomato plant pop up in a crack in the concrete next to our porch. We used the porch railings to tie it up all summer and it made for convenient snacking. 🙂
Some tips for dealing with the mess of fermenting tomato seeds
Since the seeds need to ferment for about a week, they will start to grow some mold and may even get a little smelly. And if you’re saving seed from a lot of tomatoes, it can take up a lot of space.
If it starts to bother you and it’s been more than 3 days, just go ahead and process them.
The worst thing, honestly, is if your tomatoes start to attract flies. Those tiny flies will go nutty for moldy tomatoes.
Mix some raw ACV with a drop of dish soap in a little jar to set next to your fermenting tomato seeds. It helps trap any little flies that might come around.
These ready made fly traps also work really well when placed among the cups of fermenting seeds. It lasts a long time, and the package comes with 6 refillable traps.
Rinsing and Drying tomato seeds
To rinse the seeds add fresh water to the fermented seed mixture and carefully pour off the mold. Just like it says on your shampoo bottle, rinse and repeat until the water is clear and without debris.
Then pour off as much water as you can. A mesh strainer will work to catch seeds if needed.
It is really important to make sure the seeds are completely dry before storing. Any moisture can cause mold to grow and ruin the tomato seeds.
To dry them completely, spread the seeds out onto a paper towel and don’t forget to write the variety of tomato on the paper towel.
They’ll completely dry out within a week. If the seeds are stuck to the paper towel, no big deal. Either pick them off or roll up the paper towel with the seeds on it and store it all in a paper envelope.
I recommend storing in a paper envelope vs a bottle or jar just in case you didn’t let the seeds dry out all the way. But if you’re sure they’re dry, it’s fine to store them in plastic baggies and glass or plastic jars.
How many tomatoes should you save for seed?
The number of seeds per tomato varies a lot depending on the variety. But it’s a good guess that you can get at least 20 seeds from one tomato. So a home gardener usually only needs to save seed from one tomato of each variety.
However, you can save as many as you want and share your bounty with good friends!
Storing tomato seeds
Tomato seeds will store for several years if kept dry and cool.
Once they’re completely dry, you can save them in paper envelopes, plastic baggies, empty prescription bottles, or small jars. Store them in their container in the refrigerator or a cool, dark place.
You can expect them to germinate pretty well the first 3 years after they’re saved. After that, the germination rate will start to decline, but they’re still worth a trying to grow even up to 8 years in storage.
Here’s a pretty cool thread on Tomatoville about starting tomato seeds that are over 40 years old!
Are you going to save your own tomato seeds this year?
When you’re ready to plant your tomato seeds, make sure you read our guide to starting tomato seeds indoors.