Saving Tomato Seeds to Grow Next Year

What To Do About Saving Tomato Seeds

You went and purchased a tomato plant to try. You loved those tomatoes that grew from that plant so much now you are wondering. How do you save tomato seeds? Well wonder no more! I’ll show you all about saving tomato seeds.

Home grown tomato

Home grown tomato

Whats so Special About Tomatoes

The tomato is actually a perennial plant that originated from south America. So in south America you basically can have one tomato plant growing year after year. Wouldn’t that be nice. It is believed they were first grown by the Aztecs. Around the 16th century the tomato was brought to Europe as an ornamental plant. Luckily for us these plants were able to adapt well enough in northern climates to still produce fruits in the first season.

About Those Seeds

Each one of the tomato seeds are surrounded by a gelatinous sack to prevent the seed from sprouting prematurely inside the tomato.

Sliced tomato showing Seed

Sliced tomato showing Seed

If a tomato were to be left on the vine and eventually fall to the ground and rot.

The process of fermentation would at some point begin inside the tomato.

The fermentation process is what breaks down the gel around each seed. After some time that tomato would be nothing but the stem, a little bit of skin blowing in the wind and some naked seeds lying in the dirt.

I know I’ve left some tomato plants out in the garden at the end of the year. Then in the spring, got the garden all ready to go only to find now in certain areas there were tomatoes coming up! “Volunteers” there have been many times that I would move them to a new location and keep them growing.

Roma II in the Garden

Roma II in the Garden

So even in Michigan this plant can propagate on it’s own. It may die upon the first frost. But to be able to insure it can go on through seed it drops is still pretty amazing to me. Especially considering where it’s from.

Tomato Climate Adaptation

This no doubt is from hundreds of years of people growing these plants in northern climates. The plants adapted to be able to go on another generation. This is a good point to remember. If you find a plant or vegetable you like for whatever reason. And you want to grow it from year after year. It’s best to save seeds from that particular plant.

Some things don’t make seeds so you have to figure out how to propagate that particular plant. I don’t want to get too far off track here. But the point is if you save seed from a particular tomato plant that grew “just okay” but the tomatoes were excellent. Go ahead and save those seeds and grow them out next year. Over time, from the seeds you save every year. Those plants will adapt to your particular micro climate. Eventually you will have robust plants producing those most excellent fruits you have been enjoying every year you plant seeds that you have saved.

Cross Pollination Concerns

Tomatoes are inbreeding plants and their “styles” in most types are completely retracted making cross pollination rare. There are a couple of things to remember though. Currant type tomatoes will all cross. All potato leaf tomatoes will cross. And the first double blossoms of the beef steak types can have styles that protrude and therefor could cross.

Big Boy tomato

Big Boy tomato On the vine

I like to grow a couple varieties of tomato in my garden. I always make sure to remove the first flowers of the beefsteak tomatoes. There is a good source for more information on this subject. It’s a book called Seed to Seed by Susan Ashworth you can find it here Seed to Seed.

If you like growing the potato leaf types or any others that typically cross you can use whats known as caging to keep insects from visiting the tomato plants. This is described in detail in Susan’s book.

Getting More Tomatoes & Insuring You Get Seed

When you see the flowers on your tomato plants are open. It’s a good idea to give each one a light flick with your finger. That’s how I do it. Other folks will shake there plants, indoor growers keep fans running. The important thing is to make sure the pollen inside each flower gets to the style. The better the coverage the more seed that particular tomato will produce. In turn the more seed, the bigger the tomato. Or at least the more plump that tomato will be.

Ripeness for Saving Tomato Seeds

Ripeness for eating is not the same as ripeness for saving seed. This doesn’t just apply to tomatoes either. It all depends on the type of plant or fruit. If you want to save seed from something else you must research that particular plant to find out how.

As for tomatoes, when you eat them is completely up to you! When you pick them from the tomato plant, is your choice. Fried green tomatoes are a favorite in our house. And everyone has a preference for when they think a tomato is ripe enough to pick.

When you decide to keep seed from your tomato plant keep one thing in mind. The longer on the vine the more mature the seeds will be. They will be good strong seeds with lots of vigor if you wait as long as possible for those tomatoes to ripen. These seeds will also last much longer in storage. They say tomato seeds have about 3-4 years of shelf life after being properly harvested and dried. If you grow the same variety and save seed to acclimate your favorite plant to your micro climate then no worries about how long they will last. Just keep repeating the process of saving seed and you’ll be harvesting all kinds of tomato goodness.

Selecting for Good Traits

Selecting for what you want in a tomato. Now you may notice some things about your favorite tomato and plant that you might find less desirable. But other plants have exactly or are very close to what you really want. Always select tomatoes from plants that show you the things you like in that tomato. Let’s think about what is desirable in a tomato.

  • Flavor
  • Texture
  • Color
  • Size
  • Low acid or high acid
  • Storage ability i.e. canning or drying

What about growth habits of the plants.

  • Short stocky determinate plants
  • Long vine type plants or indeterminate plants
  • Cherry, sauce, or beef steak types
  • Plants that produce over a long period of time
  • Plants that produce all at once

There are more things to select for in a tomato or growth habit of your plants but you get the idea. Look for things that are desirable to you. These are the things that made the heirloom plants everyone wants today. By saving seed for you and your family you are in fact making the heirloom varieties of tomorrow through selection of the small variances you find desirable in the plants you grow.

How to Process Tomatoes for Saving Tomato Seeds

Saving Tomato Seeds

Saving Tomato Seeds

Locate fully ripe, soft, or overly ripe tomatoes from the plants you want to save seed from. Depending on how many tomatoes you plan on saving seed from, you might be using a cottage cheese container or a food grade bucket. The process is the same regardless. Just make sure the containers you use are food grade. Plastic or glass work fine.

Anyway grab a cutting board, a good sharp knife, your fermentation containers, if other acid fruits like oranges bother you. Chances are this will too, so rubber gloves help.

Don’t forget a container for the stuff you plan to compost. If your not composting yet, shame on you! Just kidding. But really you should be composting. Especially if you want the most awesome tomatoes in the world. Tomatoes people will be completely envious of. Seriously you can check out a post about that here. Good Compost to grow great things

Getting the Seed Out

Okay remove any stems, easiest way is to just cut the top of the tomato just below the stem area. Cut tomatoes in half at the equator to expose the seed cavities inside. Now just squish the contents of the cavities containing the seeds into the container you will use to ferment in. depending on how ripe your tomatoes are you may want to just cut the stem off and squash the whole tomatos. Either way works just fine.

If you end up just putting whole tomatoes in the mix. I find a wire type potato masher works great. You can find one here, Wire type potato masher.  Just mash away until your tomatoes are like soup in your fermentation container.

The Fermenting Period

Alright this next part is so easy anyone can do it. You just have to wait. It only takes between three and four days with an ambient temperature of around 70 degrees Fahrenheit. Now after you mash your maters up and you are ready for the four day fermentation period. My wife highly suggests putting the ferment in a place that will not get rained on but is definitely out side. The garage, shed, car port, or a lean to. Just make sure the temperature doesn’t get real hot and there is no chance of rain or animals getting into your ferment. Don’t let your fermentation exceed four days. Your seeds could sprout in the ferment!

Now that you have patiently waited four days you go out to find that your fermentation container has a thick layer of mold. Who am I kidding, I’m sure you have been looking at this container every day. Any way the mold is nothing to worry about. It’s all part of the process. If you jiggle the container a little you will notice bubbles escaping the ferment. Your tomato seeds are ready for cleaning.

Cleaning Your Tomato Seeds

This is the fun part. It does not smell as bad as you think. These are fermented tomatoes, not rotten tomatoes. Okay it might be pretty bad otherwise but I’ve got an easy way for you to do this. Get a larger container, or if you are the brave soul that decided to do five gallons of tomato seeds you will need to do batches.

I usually just grab a food grade bucket and pour the ferment right into the bucket. Go outside in the grass. Now take your garden hose with it set to give a hard spray, not a solid stream with your spray nozzle. You want to break up the mass of tomato gunk into as little pieces as possible. Just add a little water at first, then use a utensil of your choice, a stick or a fork works well to break it up more. After you are satisfied that the mass is broken up well. Spray the day lights out of it. You are separating all the seeds from the tomato pulp.

Now your bucket is probably about half full with lots of pulp and mold floating around and the mixture is probably opaque and you can’t even see the bottom. Just let things settle for a moment and then poor off about seventy five percent of the water. Be careful not to dump out the seeds that are loosely lying in the bottom of the bucket.


Cleaning tomato seeds

Cleaning tomato seeds

Rinsing Your Tomato Seeds

Spray and rinse again, do this several times until the water is clear and you see your treasure “seeds” in the bottom of the bucket.

Clean tomato seeds

Clean tomato seeds

Poor off as much water as possible. Now scoop all the seeds out by hand onto a glass plate. Now then, go back into the house and get a paper towel or a hand towel to get the rest of the access water off those beautiful furry seeds. Yes furry seeds, you can’t tell when the gel is surrounding them. But they are actually furry.

Drying Your Tomato Seeds for Storage

Spread your tomato seeds out on a glass plate, or plastic if you must. just don’t use paper or the seeds will stick to it. Make sure they aren’t stacked on top of each other too badly. When saving tomato seeds try to avoid piles of seeds, you want them to dry out as quickly as possible. Don’t be tempted to use heat of any kind to dry these seeds as this could damage them. Remember you want lots of plant vigor when you plant them next spring.

Put your plate of cleaned seeds in a dry place like the top of your refrigerator, the top of a cabinet, or the back of your kitchen counter. Stir them and break the clumps of seeds apart once a day. After about a week depending on the humidity.

Storing your Home Saved Tomato Seeds

After your seeds have dried thoroughly, place them in a paper envelope of some kind, or maybe a cloth bag. Something that allows a little air to flow. If you want to store your seeds in glass containers make sure they have dried very well first or you risk the chance of mold.

After you have had them in the envelope a while. You can purchase desiccant, then put your seeds in a jar to really dry them down. This is a prerequisite to long term storage in a freezer. Most of the time I just use my paper envelopes take a look at these Paper envelopes or little cloth bags you can find them here Muslin bags. These glass containers for seed saving are very nice as well, take a look Glass containers.

For cold storage I actually have one of those little cube refrigerator’s like this one Compact refrigerator. It works well to store seeds just in case I have complete failure of the seed I save every year. I also use it to stratify special seeds that require that kind of treatment.

Storage Life and Different Conditions

So a few things to remember about seed storage conditions. It’s pretty basic, just remember cool, dry, and dark. The American Indians would make little clay pots, they would seal up their seed for next year and bury them in small clutches under ground. Then the next spring when it was time to plant they would dig up the stored seed and plant their crops to feed their families.

Tomato seeds with some care, I’m thinking an envelope stored in a box in an non-heated room will probably last four years before you start to seed substantial losses in viability. Refrigerated in a glass jar with desiccant possibly eight years. Frozen they will last a very long time probably ten or more years. But only if the moisture content was low enough not to destroy the seeds viability.

The best way in my opinion would be to grow them every year. Save seed and share with friends You’ll get so many more seeds than what you could afford to buy, and it’s fun too.

Comparison to Store Bought Seeds

This last spring I decided to buy some new tomato seeds and plant them along side my saved seed. Now please realize that seed companies are producing such large quantities. More than likely some are relying on other suppliers for at least part of the seed they purchase to re-sell to us. I think that it’s not possible on that scale for them to take the care in saving seed that you or I could. There are many good seed companies out there and I buy from them all the time. I just wanted to share what I found with you be cause to me it makes a real case for saving your own seed. Remember this is not always the true, but be aware.

Saved tomato Seed

Saved tomato Seed

First of all you may only get so many seeds per pack when you purchase. When saving seeds you get many times more than they would ever put in a store bought packet. This time the seeds from the purchased pack were very small for the same variety of tomato. Compared to the seed we had saved. This in itself was alarming. Most likely the seed company was harvesting all fruit and possibly less than fully ripe tomatoes to save seed from.

We planted the seeds at the same time. The purchased seed came up several days after our saved seed. Our plants from the saved seeds were much more robust than the purchased seed.

Germination Rates

How to tell what your germination rate is. Place 100 tomato seeds assuming you have a lot more than that, into a damp paper towel. Place the paper towel into a plastic bag.

Sprouting Tomatoes

Sprouting Tomatoes

Put the plastic bag in a warm place. Check on your seeds every couple of days to see if they have sprouted or not.

If 65 seeds have sprouted after 5-10 days then we would call that 65%. You shouldn’t have to worry too much about this if you are just saving seed for yourself but if you ever decide to sell seeds there are laws in place that must be followed.

It would be up to you to figure all that stuff out.

When I give seeds away to family or friends I only give them seeds that were produced from the previous year. That way I know they are good viable seed, after all it’s the same seed I’m planting too.

Final Thoughts About Saving Seed from Tomatoes

So Purchase seed from those companies you feel are good. Companies that are trying to preserve our heirloom varieties.

Big Boy Tomato plant

Big Boy Tomato plant from saved seed

Then save the seeds you can so you can enjoy the plants and tomatoes you like to eat. Just from the stand point and gratification one gets from taking something full circle is enough for me.




Share your tomatoes with others, share your seeds with others.



Thanks for reading,


Tags: , , , , , , , , ,

No comments yet.

Please Leave your thoughts