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How to Save Tomato Seeds: A Step-by-Step Guide

how to save tomato seeds

Learn how to save tomato seeds, including what you’ll need, the best time to collect the seeds, and how to properly store them.

Saving tomato seeds is a fun and easy hobby that can save you money and provide you with a sense of accomplishment. As a hobby gardener, I love growing my own tomatoes, and saving the seeds allows me to grow the same delicious varieties year after year.

Last year, it was my first year growing so many varieties of heirloom tomatoes. I wanted to test as many as possible, so that this year I know exactly what to sow, which are the best varieties in terms of looks, taste and resistance to diseases. I will showcase below some of the tomato varieties I grew last year, in both the greenhouse as well as outside. I saved the seeds only from the best of them and I will sow them this spring.

Some of the varieties I grew last year are (they’re not all in the photos, I will specify the varieties where I remember them):

  • Big red tomatoes – Suceava variety (this is a popular Romanian variety)
  • Ananas  Tomatoes
  • Black Cherry Tomatoes
  • GiaGiu Tomatoes
  • Mushroom basket Tomatoes      
  • Green Zebra Tomatoes 
  • Lemon Giant Tomatoes 
  • Gigante Del Re Tomatoes            
  • Green Velvet Tomatoes
  • Tangerine Tomatoes      
  • Lost Marbles Tomatoes 
  • Orange Bourgoin Tomatoes        
  • White Cherry Tomatoes
  • San Marzano Tomatoes

My top favorite where: Mushroom Basket, Green Zebra, GiaGiu, Lemon Giant, Green Velvet, White Cherry, Orange Bourgoin and Tangerine. I will probably create a separate post about the different varieties of heirloom tomatoes I have tested so far.

heirloom tomatoes

In this guide, I will walk you through the process of saving tomato seeds, including what you’ll need, the best time to collect the seeds, and how to properly store them.

Contents:

  1. Supplies needed for saving tomato seeds
  2. Saving tomato seeds with fermentation – best method
  3. How to you save tomato seeds without fermenting?
  4. Treating tomato seeds
  5. Storing tomato seeds
best heirloom tomatoes

Supplies needed for saving tomato seeds

First, you will need to gather some supplies. To save tomato seeds, you will need the following:

  • Ripened tomatoes from the variety you wish to save seeds from
  • A small bowl or container
  • A spoon or fork
  • A strainer or cheesecloth
  • A labeled envelope or small Ziplock bag or container to store the dried seeds in.
  • Paper towels
  • Optional: small glass jar, if using the fermenting method.

Saving tomato seeds with fermentation – best method (recommended!)

This is the method I used and it is the best method, even though it may be a bit more time-consuming than the other one, it brings better results.

Time needed: 2 days

Follow these steps and learn how to save tomato seeds using the fermentation method. Through fermentation, the protective gel layer on top of the seeds, which prevents them from sprouting, is removed.  

  1. Choose ripe, healthy tomatoes

    Make sure the tomatoes you select to save seeds from are fully ripe and free from disease or damage.

  2. Extract the seeds

    Cut the tomato in half and squeeze the seeds and gel into a container.

  3. Ferment the seeds

    Cover the container and let the seeds ferment for 2-3 days at room temperature. This process helps to remove the gel coating on the seeds, which can inhibit germination.how to save tomato seeds-fermenting-method-metoda-fermentarii-pentru-semintele-de-rosii

  4. Rinse the seeds

    After fermentation, rinse the seeds thoroughly to remove any remaining gel or debris.

  5. Dry the seeds

    Spread the seeds out on a paper towel or coffee filter and let them dry for several days. Make sure they are completely dry before storing.

  6. Store the seeds

    Once the seeds are dry, store them in an airtight container in a cool, dark place. Be sure to label the container with the variety and date of harvest.

  7. Test for viability

    Before planting, test a small sample of the saved seeds to make sure they are still viable by placing them in water. The seeds that float are not viable and should be discarded.

tomato seeds

How do you save tomato seeds without fermenting?

To save tomato seeds without fermenting, you can follow these steps:

  1. Choose the ripest and most flavorful tomatoes from your garden, and slice them open. Scoop out the seeds and surrounding gel into a bowl. Be sure to remove any bits of tomato flesh, as this can cause the seeds to mold.
  2. Once you have collected the seeds, it’s important to let them dry. Spread the seeds and gel mixture out on paper towels or cheesecloth, and let it sit in a warm, dry place for several days. The seeds will separate from the gel and become dry and brittle.
  3. Once the seeds are dry, you can store them in a container with a tight-fitting lid. Label the container with the variety of tomato and the date you collected the seeds. You can also include any notes on the tomato’s characteristics or growth habits.
sweet green tomatoes
Suceava tomatoes and Green Velvet
mushroom basket and green zebra tomatoes
Mushroom basket and Green Zebra

Treating tomato seeds

I don’t personally do this, but it is recommended when you plan on sharing tomato seeds with other people, to decrease the risk of disease transmission.

When saving tomato seeds, it is important to treat them to prevent the transmission of any diseases. Once you’ve followed the steps above and you have viable seeds, you can treat them with a solution of 10% bleach and 90% water for about 10 minutes to kill any bacteria or fungus. After this, rinse the seeds thoroughly with clean water and dry them on a paper towel or seed drying rack before storing them in a cool, dry place. It’s also good to label them with the variety name, date collected and any other relevant information.

large mushroom basket tomato
My largest tomato last year – the incredible Gigante Del Re.

Storing conditions for saved tomato seeds

The perfect storing conditions for saved tomato seeds are a cool, dry, and dark place. Ideally, the temperature should be between 32-41°F (0-5°C) and the humidity should be low, around 40-50%.

The seeds should be stored in an airtight container, such as a glass jar or plastic bag, to keep out moisture and light. It’s also good to label the container with the variety of tomato and the date they were saved. It is also important to note that tomato seeds can last up to 5 years when stored properly.

giant tomatoes and yellow cherry
tomatoes in greenhouse
Green Zebra and Tangerine I thing, but these photos were taken a bit later in the season and they were attacked with some kind of disease.

Saving tomato seeds is a fun and easy way to preserve your favorite varieties and save money on your gardening. With a little patience and attention to detail, you’ll be able to enjoy the fruits of your labor for years to come. Happy gardening!

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