How to: Save Heirloom Tomato Seeds

Saving your own tomato seeds is rather fun and has all sorts of benefits. Preserving heirloom seeds, ensuring a supply of your own favourites for next year, helping protect seed diversity, making a giant mess of stinky fermenting goo, it’s all there! It’s also pretty easy.

As part of our seed selling business we save fairly large quantities of tomato seed but the process is the same whether you are saving from a pile of heirloom tomatoes or from a paticularily tasty one you just sliced up for lunch.

First things first, you need to get your tomato seeds out of the tomato.  You can slice them in half, in quarters, scoop some out of the one you’re eating or just use my preferred method: Squishing. A serrated grapefruit spoon makes a great seed saving tool, especially when dealing with smaller cherry tomatoes. Just cut them in half and scoop out the inside of the tomatoes leaving the skin and outer flesh behind.

Next the seed pulp is ready to be combined with water in a container.  Glass jars are simple and food safe, but yogurt containers and tupperware are perfectly suitable. The only really important factor is that the container needs a lid. It’s going to get stinky so the lid is not optional.

Make sure to label each variety as you go as tomato seeds all look very similar and the coloured pulp is going to break down.

Place them out of direct sunlight and walk away for a few days. You’ll start to see the good seeds settle from the pulp down to the bottom of the container.

Now things will start to ferment. This fermentation process is breaking down the protective coating on each seed. After a few days and once you have a good layer of fuzzy stuff, dump it off, leaving the seeds in the bottom of the jar.  Any seeds at the top are duds, the good stuff is all at the bottom.  Top up the jar with some clean water and let it all happen again.  Once the seeds are starting to settle cleanly at the bottom they are done. Be careful not to leave things unsupervised for too many days as the seeds could start germinating.

Once the seeds are ready, pour off any remaining pulp and mould.

Using a strainer, give your seeds a final rinse. They should be looking rather naked by now.

Now you just need to let them dry.  A stack of clean rags or old tea towels work best, as paper towels sometimes stick.

Once again, label your seeds. Package them up a few days later when they’re perfectly dry and you’re set.  Next spring you’ll have more tomato seeds then you can plant.  Trading them with fellow seed savers and planting a few extra for gardening neighbours is highly recommended.

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52 Responses to “How to: Save Heirloom Tomato Seeds”

  1. Okay, I came across your blog at the perfect time! We inherited a garden with the house we just bought, and I’m looking to revamp it a little with things we’ll eat more often. Do you mind if I email you some questions?

  2. Margaret Umble says:

    How and where you you store them till the next Spring? Room temp/dark?;freezer?

  3. lLou Jean says:

    I actually like spreading them out n a paper towel. Before doing so, I also actually write the name right on the towel. If you spread them out nice and thin, they will stick to it. Then dry I roll them up and seal in a zip lock bag, and next year they’re all ready spaced and all you have to do is lay the paper towel on top of the dirt in whatever container your using to sprout them and cover with dirt. If you want just a small number, you can always just remove that number from the towel easily as well, or just cut off a small piece of it..

    • mbr says:

      ILou, where do you store the seed & you use them the following year??? Does it matter if it sits around more than a year???

    • gracie says:

      ILou Jean…that is a Great idea. I also sprout seeds on a damp papertowel in a pie pan…then just walk them to the garden.

    • Alawon.B says:

      This is the 1st year I’ve grown tomatoes ~ I got Caspian Pinks. If they’re as good as I imagine they’ll be, I’ll be saving some seeds. Think I’ll try drying ‘em on a paper towel :~)

  4. Tim Fikse says:

    Maybe I’m dense, but I don’t understand the need for all the early storing and fermenting in jars. I dry my sliced tomatoes, take some seeds out, and then store them. I see some value in eliminating the duds, but is there anything else I’m overlooking?

    • admin says:

      Hi Tim,
      that’s a good question. Tomato sees have a protective layer that you want to remove for storage and germination issues. If what you are doing works for you then keep it up.

  5. judith petrou says:

    I too just squash the tomato, seeds of cucumber,squash,pepper, onto newspaper. Allow to dry in full sun scrape off or cut up paper and store in envelopes or plastic depending on how long one wishes to keep them. But do love what I learn from this site.

  6. Annick GOBLET says:

    I also add a little bit of yeast in the water. I got the tip from a Dutch pro

  7. Alexis says:

    will this process work on any seed? Cucumbers, squash etc? if not, is there a section on your site that deals with other seeds for harvesting and banking them?

  8. Dena says:

    A paper plate also works very well.
    I have only saved seeds from my outdoor tomatoes as I only grow one variety in the garden. However, I grow several in the greenhouse. What is the likelihood of tomatoes in a greenhouse cross- pollinating? Is there any point trying to save seeds from hybrids or will the seeds likely produce something very different? For example, I grow “sun gold” in the greenhouse. I think they are a hybrid, but the seeds are often hard to find and I would like to save my own.
    Thanks

    • admin says:

      I don’t bother saving from hybrids. A few years ago I experimented with saving seeds form a hybrid and yes, you get one of the parent tomatoes which is not a whole lot like the tomato you saved seeds from. There are other yellow cherry and mid sized tomatoes if you want to try an heirloom. Jaune Flamme is pretty great, orange and sweet and about the same size as the sun golds.

    • CP says:

      If you save seeds from a hybrid, you will get viable seeds, but they will have a mix of traits. Some of the offspring will be like Sungold, some will be like Sungold’s parents, some will be something else. To have a variety that will give you predictable offspring, you will need to stabilize the variety. To do that, you need to save the seed over many years, each year selecting the best tomatoes, and eventually you will get your very own variety. There are several stabilized varieties derived from Sungold. Yours will be adapted to your own climate. Hybrids are how open-pollinated varieties begin.

      My favorite open-pollinated Sungold-like variety is Gold Nugget.

  9. Suzie says:

    I bought all heirloom seeds this year, and many of them are different types of the same plant, example roma tomato and cherry tomato. How do I prevent cross-pollinating so I can save the seeds for next year? Is this something that I need to worry about when saving the seeds?

    • admin says:

      Give your plants a nice amount of space and you should be fine. A few feet apart at least.

    • David Story says:

      If you want to save a perfect example of your tomato you need to bag your blooms prior to pollination. Without bagging, you have a probability to end up with a hybrid version of what you grew the prior year. Many will argue that cross pollinating tomatoes are a myth but I tend to disagree. The USDA distance to assure of no cross pollination is a minimum of 40′ between plants and that doesn’t take into consideration that the pollen isn’t carried from plant to plant by the farmer.

  10. Leah Nosack says:

    I saved some seeds from a black cherry tomato a few years ago. Gathered the seeds from the tomato, rinsed them, dried them on a paper towel on my enclosed porch. Forgot about them. Next spring I was out sweeping the porch, swept up this old piece of paper towel from the cement floor and found my seeds. Planted them, had tomatoes. Not a recommended method LOL. I think seeds can be hardier than we think. The temperture on that porch in the winter was zero and poss lower at times. Wish I had kept saving those seeds as they are hard for me to find here.

  11. Joanne Frank says:

    I have grown tomatoes from seeds as well as plants. One year we left the plants in because we were on vacation in the fall and when we came back we had a snow blizzard in early October. I forgot about my garden and next spring my tomato seeds automatically re established themselves on their own. I was a bit surprised when my husband was raking the garden in early spring and there werer the tomato plants coming up all by themselves. I probably wont be able to replicate this again because it had to do with the weather. But just thought I would toss this out for fun. The lazy way of growing tomatoes from year to year without the work. lol.

  12. Suzanne Brown says:

    When I cut up tomatoes, squash, cantalope, cucumbers, peas, beans or peppers, I place the seeds into a fine wire mesh strainer. I rinse them with lukewarm water and then place them on a piece of “used/recycled” paper or newspaper. I write the seed type right on the paper. After a few days on my back porch they’re ready to package. I carefully pick them off the paper and place them into recycled envelopes that I get in junk mail . . .label the envelope and file it in a cardboard box. I sometimes just plant the paper with the seeds stuck on it, as the paper breaks down so fast it’s not an problem. I might not get the same germination percentage that you do after the fermentation cleaning process, but that’s just too messy and complicated. Plus I must admit that some of my favorite tomato plants are the mystery ones that sprout from my compost.

    Sometimes nature is best left undisturbed.

  13. Donna Peck says:

    Can I plant tomato seeds directly in the garden- or must they be
    Started early indoors? I live near Pittsburgh, pa.

    • admin says:

      Hi Donna, They do better when you give them a head start indoors by a few weeks but you can direct sow in the garden, your season will just be shorter.

  14. Leah Nosack says:

    I’ll keep that in mind. I’m on the coast now, previously midwest. This is my first full season here. I’m about a 1/4 mile off shore and I’ve been told tomatoes will not grow here. I have a whole plan of how I’m going to proof them wrong, so we’ll see. If I have success this year with the Cherokee Purples I’ve chosen for my experiment I may be bolder and see if you have seeds for next year. I never even thought about looking on Etsy for seeds. Thank you for the link.
    Leah

    • CP says:

      You live in the Seattle area? Tomatoes grow here, but large beefsteak-like tomatoes are unreliable without a greenhouse. I didn’t have much success with Cherokee Purple. The easiest are cherry tomatoes – I always get tons. Medium sized tomatoes also do fine. There are even local heirloom varieties (Seattle Best of All & Sixth Avenue) and a tomato breeder (Tom Wagner, his most famous tomato is the Green Zebra). :)

  15. Becky says:

    I would like some heirloom seeds. I am starting some keyhole gardens. Thanking you in advance!
    Becky

  16. Joan Marino says:

    I was living in Bandon, Oregon about four blocks from the ocean and was living in a rental with a 6 x 8 raised planter box in the back yard. My husband built a “greenhouse” onto the box and I grew Cherokee Purples to die for!! Yes you can grow tomatoes on the coast, best in a green house though. We now live in Coos Bay and I grew cherry tomatoes in our green house and they gave us all we could use and were wonderful. My cousin has a very large garden, but lives further inland a little from me and she grows her cherry tomatoes outside, not in a green house and does fine. I am going to try it this year, but will have the larger tomatoes in the green house.

  17. Greta says:

    I was wondering if a good way to store seeds for long term storage would be to vacuum seal them in canning jars? I have not been able to find any information recommending that, and would like to know if the lack of oxygen would damage the seeds? Thanks in advance!

    • admin says:

      HI Greta, I’d be more concerned about any remaining moisture creating mould.

      • Greta says:

        Thanks for the reply, I would be putting desiccant in to absorb any residual moisture, my concern is that I would damage the seed if there was a lack of air.

  18. Judy says:

    Hi. The tomatoes picture your have on this page, top left , right below post title, what variety is it? I had something similar when I was in Italy last year and it was one of the best tasting tomatoes I’ve had. Thanks!

  19. Renae says:

    Tomato seeds are wonderful and its fun to save them but I really have to mention you to save HEIRLOOM and/or ORGANIC seed. Make sure you are not using GMO seed, they are not only illegal to save but often will not germinate and your efforts will be in vain. Besides, Heirlooms taste wayyyyyyy better anyway.. :)

  20. Flow says:

    Hello – to the Questions about possible Cross-pollination.
    The chances depend highly on the structure of the flowers.
    Especially cherry tomatoes as well as some “bigger” or “in-between” varieties have a rather closed flower ( pollination needs some kind of outside movement – best is the so called buzz-pollination of bumble bees – but wind works as well). in this case self pollination is much more likely than cross pollination. i have at least three cherry varieties growing together each year, harvesting the successive seeds, and yet not one “intermediate” plant was found in the follwing year.
    Other types on the other hand have rather opened flowers ( especially many of the bigger varieties) so in this case pollination through other insects is more likely, and through this as well cross-pollination.

    it is therefore adviseable to examine the flowers closely and then decide about a possible risk of crossing.

  21. sherry says:

    thanks for the information! it made me want to do some planting too

  22. Robert says:

    I agree with some mentions above … all of that soaking of the seeds is just not necessary.

    When I slice a tomato on the cutting board I mop up the juice and seed mess with a paper towel. I store that in envelope until I’m ready to plant the seeds next year.

    Simple and it works just fine. My brandy wines are up, about three inches tall, strong looking and will be ready to plant out in a couple of weeks.

  23. glenn says:

    we ran a plant farm and nursery for 20 years— tomato seeds will last for 1 year and possibly longer stored at room temp. but will last for years stored in a frig. and will last a lifetime stored in a freezer.

  24. Pam Sellards says:

    Thanks! a coworker gave me some plants that came from heirloom seeds his grandparents brought over from Italy in the 70′s. The plants had been in the family for generations. now I know how to save them!

  25. Christina Winton says:

    I’m so jealous Pam Sellars!

  26. Margaret says:

    can you freeze a whole tomato and save them that way?

  27. […] CREDITS: I’d like to apologize to Laura Watt over at ETSY…..Her original posting contains her Photo that I posted in my article erroneously…. You can see her posting here : http://cubitsorganics.com/2012/08/how-to-save-heirloom-tomato-seeds/ […]

  28. […] UPDATE: In October of last year I included a picture with my article that actually belonged to Laura Watt. I published that photo without her permission and I want to give her credit for that photo…..obviously it was “High Quality” or I wouldn’t have used it myself. You can see her photo at her site as follows http://cubitsorganics.com/2012/08/how-to-save-heirloom-tomato-seeds/ […]

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