Seed Saving Tomatoes

Seed Saving – Tomatoes – How to

Tomatoes are on my list as being one of the most important vegetables when it comes to seed saving.

Before I found out about Monsanto buying Seminis — I always grew mostly Big Beef, Beefmaster, Better Boy, Burpee’s Big Boy, Celebrity —all the great Seminis varieties.  They really were my favorites.

It was a blow not to have them, but I started right in on finding a replacement.  I’m going to try a few new ones every year — but you know as well as I do (especially if you’ve gardened for a while) that finding “the perfect tomato” could take a lifetime. My garden is only so big.

My second approach — and in retrospect the best approach — was to save the seed from the last Big Beef I grew. (I chose the Big Beef because that’s the seed I had and I certainly was not going to buy anything else from Monsanto.)  I had no idea what the offspring would look like or taste like since hybrids don’t always produce offspring like the hybrid itself.

(I think lots of growers have tried to find out the secret of what tomatoes were used as parents to Big Beef — but to my knowledge it’s a well kept secret.)

Pick Your Best Tomatoes When Saving Seed

To use for seed saving, I picked the tomato that exemplified everything I wanted in a tomato.  Ideally it would have been better if I’d had one of those beauties from several of the plants of that same variety.  That would have given me a bit more diversity  even within the same variety.

This is the tomato in my side border this year.  Usually all my plants look like this — with thick foliage covering the tomatoes.

I’ve had great success.  The tomatoes grown from that seed have been everything I could ask for.  Beautiful — large — delicious — and bountiful!

If you’d rather not spend the years necessary to get a good open pollinated Big Beef, you can order seed from Gary Ibsen (THE tomato man) whose already done it for you. Here’s the referral link.

The tomatoes grown from that seed have also been the most productive, the best tasting and have the prettiest tomatoes. What amazes me even more — I had some trouble with Early Blight — to the degree I’ve never had before in 35 years! I kept pulling the leaves off —– leaving bare branches — trying to stop the spread of the blight. The plants just kept churning out tomatoes and they still are.  It’s amazing!

Early blight afflicted these tomatoes this year.  I kept pulling off leaves to stop the blight.  I can’t believe I still got so many wonderful tomatoes and the plants are still producing!

In a few more years I hope to have a tomato that is perfectly adapted to my garden and conditions. (Keep in mind you can also do this by saving the seed from an heirloom or any open-pollinated tomatoes. If you save the seed from your favorites this year — within 3 or 4 seasons the descendants of those seeds should be perfectly adapted to the conditions in YOUR garden.)

To Ferment or Not to Ferment

Although I know a gardener who has been saving seed for years without fermenting them, his tomatoes always have some type of blight and by August are totally without a leaf  and black looking.  I’m not a scientist and certainly can’t prove that it’s due to not fermenting the seed he saves, but fermenting seed is said to kill pathogens that may (if left) effect the crop that grows from the seed.  I’ve done it both ways. After seeing blight rear its head in my garden this year, I will go only with fermenting my tomato seeds — even if it’s just precautionary.

Diane Linsley of Diane’s Flower Seeds says this also improves the germination rate of the seeds. Diane should know because tomatoes are one of her specialties and she grows lots of them.


Fermenting  may sound difficult if you’re new to seed saving, but it’s really a bit easier than not fermenting because it’s the easy way to get rid of all the gel on the seeds. (As well as the pathogens.)

Here’s How to Save Your Tomato Seeds

  • Which Ones to Save

Save your seed from several fully ripe tomatoes that exemplify what you want in a tomato.  If possible — save your seed from different plants of the same variety.  (Sometimes that doesn’t work for me if there is one plant that I like the best and that gives me the very best tomatoes.) (Update 2019 – I saved seed from 16 different plants this year.  Yeh diversity!)

  • Time to do it

The best time for me to save my seed is as I prepare a meal.  That way — after I take the seeds out — I can serve the tomato with the meal. Anytime it works for you is fine.

  • Cutting and Removing the Seed

I slice my tomato around the middle which leaves the top whole rather than slicing through the stem end. This makes it really easy to see and remove the seed. Use your finger, a knife, a spoon or a grapefruit spoon.  Anything that works for you.

  • Label your Container

Place the seed in a container and add a couple of tablespoons of water.   A plastic cup or a glass jar will work just fine. If you’re doing more than one variety — be sure you label it. (I didn’t one time and I had to do the entire process again so I could be sure what seed I had.) I write the name on a piece of paper and tape it onto the jar.

  • Let it Ferment

I place the cup or jar with the seed on our enclosed porch where I will be reminded to check it, but not so close that I have to see or smell it all the time when it starts to ferment— which takes almost all week.  The warmer the room the faster it will ferment. If you want to leave it on the kitchen counter you might cover it lightly with plastic wrap so the smell won’t be as strong.

A white mold will develop on the surface of the liquid. When the white mold covers the surface fermentation will be done. Seeds that are good sink to the bottom. Non-viable seeds and debris rise to the top. Your seed should be free of any gel.

NOTE: It’s important to watch this process and not allow the seed to stay in water beyond the point of fermentation because they’ll start to germinate.

  • Separating the Seed from the Debris

Add more water: about twice what was in the jar.  Stir well. Let rest for a couple of minutes.

When the good seeds fall to the bottom again, gently pour off the top layer.  Add more water and repeat this process until all debris is gone.  Only your clean seeds will remain.

  • Air Dry the Seed

I put seeds in a small strainer and let that sit on a hand towel or paper towel to absorb the water. Then I put the seeds on piece of window screen that Bill cut out for me. (About 4 x 4 inches square.) I just lay the screen with the seed on it on a plate and let them dry out.

If you don’t have a piece of screen you can use a plate or something made of glass, ceramic, or stainless steel.  You can even leave them in the strainer.  But be sure to check everyday and move the seeds around.  You want them to dry and not clump together.

Fermented and clean seed air drying in dishes.

The more humidity in the air the longer the drying process takes — so be patient.  In order to get the most fertile seeds possible air dry only.  No artificial heat like a dehydrator or microwave.

The drying process should take about 3 weeks.

  • Test Your Seed

If one breaks it’s dry.  If it just bends you need to let them dry more.

  • Store

Store in a cool, dark, dry place.  For more detail on storing seed review my post Seed Saving – Seed Storage.

Final Thoughts

If you’ll follow this simple procedure you’ll have strong fertile seeds that should germinate quickly next spring. Not only that, but in a few years you’ll have a tomato perfectly adapted to YOUR garden.

And if stored properly, your tomato seed could be good for 5 years or more!


Related Posts:

Seed Saving – Seed Storage

Monsanto – Don’t Entrust Your Life to Them


Organic gardening is easy, effective and efficient — and it’s a lot healthier.


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