How to Harvest and Replant Tomato Seeds




Introduction: How to Harvest and Replant Tomato Seeds

In this tutorial I'm going to show you how to harvest seeds from ripe tomatoes. Planting seeds and letting them start to sprout is a nice gift to give to someone who either loves plants, sustainability, or food!

This is a great project if you either have your own tomato plant, or is lucky enough to get a fully home grown tomato so you can start your own plant.

Let's get started!

Step 1: Parts and Tools

You are going to need the following:

  • A ripe tomato
  • Coffee filter
  • Saran wrap
  • A glass
  • Kitchen knife
  • Cutting board

Step 2: Getting the Seeds

To get out the seeds start by cutting the tomato lengthwise opposite direction of where the stalk grows. This opens the tomato to easily get the seeds out.

Using the tip of a dull knife or a spoon scoop out the seeds. Take care to not scoop out too much of the tomato flesh as we only want the seeds.

Step 3: Fermenting Seeds

Chuck the seeds into the glass. You can add a couple drops of water, but not too much as this prevents the seeds from properly fermenting.

Cover the glass with cling film and poke a few holes in the top.

We are now going to ferment the seeds. This makes the seed separate from the rest of the tomato flesh, as well as becoming hardier for longer term storage.

Place the glass in semi-cold to room temperature area without much light. I used the inside of a cupboard.

The seeds are going to be there for a one to two days. Don't worry if there appears a layer of mold this just means the fermenting process worked! If the seed lay wet like this for much longer than a couple of days they will start to sprout. This is good if you plan to immediately replant the seeds, but not something you want if you plan on storing the seeds for later use.

Step 4: Cleansing and Drying the Seeds

After a couple days of fermentation pour the seeds into a coffee filter. Carefully rinse the seeds with some cold running water. Let all the water run through and you can put down the seeds for drying.

Let the seeds dry out of direct sunlight and when they're completely dry you can put them in a clean coffee filter. Wrap it up and open whenever you feel like replanting the seeds.

Step 5: Replanting

Congratulations you just finished harvesting seeds for replanting tomato plants! Planting seeds and letting them start to sprout is a nice gift to give to someone who either loves plants, sustainability, or food!

You can either plant the seeds immediately or wait until you want to gift a plant or another tomato plant in your window sill!

To replant simply get some plant soil in a pot, add the seeds and cover them with about one centimeter (half an inch) of top soil. Keep the soil wet in the start and with a lot of sunlight.

Tomato plants grows really fast so you should start to get visible sprout within a week.

Step 6: On Choosing the Tomato to Harvest Seeds From

A note on the type of seeds as pointed out by Hammerguy84, the seeds needs to come from heritage tomatoes and not hybrids.

What this means is basically that it's not possible to regrow seeds from store bought tomatoes. This is because regular store bought tomatoes are hybrids made to grow faster, which still creates tasty and healthy tomatoes. However, the seeds of the tomatoes does not contain the same DNA as the mother plant.

If you want to regrow tomato plants from seeds, simply be sure and get a tomato that's already homegrown, or you could look at a farmers market. If you've already grown tomato plants from seeds from a gardening store, or know someone else that has done this, those tomatoes are the perfect candidate for harvesting and replanting!



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    20 Discussions

    Each year I grow about 400 tomatoes, mostly for sale. I start about 25 them in a 3-4" pot or cottage cheese carton. Once the first leaves are well developed I remove the soil and plants from the container and transplant each to a cell in a 4-pack. As the roots start to crowd the cell I then transfer each plant to a 4" x 4" pot where it stays until ready to be planted at home or to be sold.


    I often wondered how to do this

    Thanks for sharing

    Very nice. the method is fool proof and very well explained. Keeping the seeds evidently works only in heirloom tomatoes (and other plants).

    I'll add that the best way to keep the seeds is in the fridge in a sealed bag.

    Heat shortens dramatically the life of seeds, and tomatoes seeds after spending 6 months at more than 30 degrees Celsius have a high fail rate germination.

    3 replies

    Thanks mate, I didn't know about keeping the seeds in the fridge! Fridges do have pretty humid air, so the sealed bag is important!

    You are welcome. Yes the sealed bag is important, it keeps out also the fungus, the main killer of seeds a part the heat. Tomato seeds can be kept until 5 years in the fridge with a good germination rate. It's important to keep always seeds of the former years as the plantation of one year may be a failure, or worst the tomatoes appears to be hybrids when grown, so you have to go back 2 years before to get the pure breed again.
    Another important thing before planting, it's leaving the seeds out of the fridge 2 or 3 days in the sealed bag (so no condensation), and after to soak the seeds one night in water at room temperature. That improves highly the germination rate.

    Interesting when you have to consider generational differences between the seeds! Five years is a long time they hold up so it shouldn't be a problem.

    I've always fermented the seeds because yes you do get a lot higher rate of germination. You can actually just let a tomato rot with similar results . Which is the reason why I usually use tomatoes that are starting to go bad, no sense in wasting a good tomato.

    1 reply

    Spot on! When a tomato is rotting the glucose in the flesh has actually started to ferment.

    Tomatoes are also very easy to clone. Take the shoots that are located between a main stem and any of the main compound leaf stems. These are the shoots that will eventually produce fruit. A treatment of root hormone will be beneficial but not essential to producing a healthy plant. Plant the stem in a good quality potting soil and water as needed. Roots should be seen within a week and the successful clone should be ready for the garden when new growth produces a second layer of leaves. The major reasons for failure are over or under watering. Tomatoes do not seem to have problems with a soil surface level and can be planted a deeply as you wish. I like to buy quite leggy plants at a huge discount and plant them with a post hole digger if the topsoil is deep enough. this gives me an edge on the very dry summers of the Pacific NW.

    1 reply

    Fantastic to know tomato plants are so hardy! I'll have to try that some time.

    This will work with hybrid tomatoes, BUT you will not get the same kind of tomato as the one you got the seeds from. You will get a mystery tomato that you may or may not like. Also, I might add; you will have better results if you make sure the tomato is fully ripe before removing the seeds.

    3 replies

    If you wanted to get all Gregor Mendel on your tomatoes you could always experiment and make your own hybrids.

    Of course you would need to keep examples of both parent plants to reproduce the F1 hybrid seed.

    Sounds like an awesome experiment for someone a bit more patient than me!

    Yeah that's definitely true! I just don't consider it an option myself though, because I harvest seeds to get more delicious tomatoes!

    Very helpful! I'm going to try this with some heirloom tomatoes from the farmers market!

    1 reply

    Best of luck! Hope you'll post a picture when they sprout!

    Great info to know! I'm glad to see another self sustaining gardener here! On a small note, make sure that your tomatoes aren't hybrids if your starting this for the first time. The tomatoes need to be heritage tomatoes in order to harvest and replant seeds. Great ible and thanks for sharing!

    1 reply

    You're absolutely right! Thanks to you I added another step now just to clear up what kinds of tomatoes to look for when harvesting seeds!

    I did not know about fermenting the seeds to increase the odds of germination. I would have just rinsed the tomato goo off of them and let them dry out (which will also work but the odds of germination are apparently lower).


    1 reply

    Yeah mate, as you said it increases the odds of germination. This is especially the case if you want to store the seeds instead of replanting them immediately!