How To Save Tomato Seeds

Introduction

Knowing how to save tomato seeds is a great skill to learn to help you become more self-sufficient. In this post you’ll learn everything you need to know to save your own tomato seeds for next year. Saving tomato seeds at home is a simple process. Whether you want to save cherry tomato seeds, beefsteak or regular varieties, the process is broadly the same for all tomatoes. 

The only conditions are that you’ll need to have successfully grown some open pollinated tomatoes this year, or maybe you can find a friend or family member who has, if you haven’t. 

Why Open-Pollinated Tomatoes?

Open pollinated plant varieties will produce seeds that, if planted in the following season, will produce the same variety of plant that the seeds were saved from, providing no cross pollination has taken place (tomatoes do not cross pollinate easily). All heirloom tomato varieties are open pollinated, as are lots of newer varieties that are stabilised. 

This is contrary to F1 Hybrid varieties that are bred from two different parent plants with distinct traits. When you save the seeds from hybrid tomato plants, and plant them the following season, the same plants as their parent plant do not always grow. The plants that grow may have much stronger traits of one of either parent, and may not be desirable.

Why Save Tomato Seeds?

There are lots of benefits to saving your own tomato seeds, other than the obvious cost saving. You can contribute to preserving varieties that may otherwise become less available. 

You will always have the option of growing the tomato varieties you like most, and become less dependent on companies like ours. You’ll be free to select the best performing plants of a crop that you’ve grown, save those seeds, and you are on your way to maintaining a strain of seed that performs well in your specific area.

Sungold Select II 

Below you will find all of the steps, with pictures included on how to save your own tomato seeds. The tomatoes pictured in the examples are a cherry tomato called Sungold Select II. They are an open pollinated version of the extremely popular F1 hybrid variety “Sungold”. They are a very sweet cherry tomato that has a great tangy taste.

We have grown a good crop of this variety this year and we hope to have it for sale by the end of October 2023.

Sungold Select 2 Tomatoes growing on a vine.

How To Save Tomato Seeds

Whether you want to save heirloom tomato seeds, or any other variety, the good thing about collecting tomato seeds is that it is not that hard. It is pretty much the same process for all tomato types, with only slight differences. The process is detailed below.

Selection Process

The first thing to do is to select some of the best ripe tomatoes you have growing to collect the seeds from. Make sure there is no disease on the fruits, and do not select fruit that might have split. You don’t want these traits in future generations. 

You can be specific here with what you want to select for, maybe one plant produced fruit earlier in the season than the others. If you select from this plant, you’ll help to bring that trait forward to future generations. 

Or perhaps the fruit on one plant was sweeter than the fruit on all the others. Saving the tomato seeds from this plant will help to bring forward the trait of sweet fruit to the next generation.

How To Harvest Tomato Seeds

Once you have selected the tomatoes you want to save the seeds from, cut them in half and scoop out the gel that contains the seeds inside the tomato. Place this in a container of some sort.

Sungold Select Tomato cut in halfSeeds being removed from a tomato by a spoon

Another way of harvesting the tomato seeds is to make a slit in the bottom of the tomato with a knife. Then squeeze the tomato until all of the seeds have been pushed out of the slit into the container.

How To Ferment Tomato Seeds

When harvested from the fruit, tomato seeds have a gelatinous coating around them which will eventually break down. This gelatinous coating prevents the tomato seeds from germinating inside the tomato. 

If this coating is not removed from the tomato seeds, germination can take a very long time once the seeds are planted. The rate at which the seeds germinate is also quite erratic. To remove this growth inhibiting coating from the seeds, we must ferment them.

Put some film over the container and poke some holes in it to allow air in. The film keeps fruit flies away from the mixture. Then allow the container to sit still in a warm area of the house for 3 to 4 days.

Seeds and gelatinous mixture from tomatoTomato seeds prepared to be fermented

After this time you will notice a not so appealing looking layer of mould growing across the top of the mixture of seeds and tomato insides. This is good, as the fermentation process has now taken place. This process of fermentation removes the growth inhibiting coating on the tomato seeds.

Tomato Seeds fermented with mould on them

How To Clean Tomato Seeds

Have a sieve on hand, and then pour some water into your container to loosen everything up. Pour it all into a sieve. The mould coating should remain in one piece. Be sure to wash any seeds off of it that might be stuck underneath it. Then you can discard it. 

Breaking mold of fermented tomato seedsRinsing tomato seeds in sieve

Continue to rinse your seeds in the sieve until they look clean. If there is some bigger debris that won’t go through the sieve, you can put all of the mixture including the seeds back into the container, and fill it with water. The seeds should sink to the bottom of the jar, and you can then pour the water and big debris out of the jar. Put everything back into the sieve, and keep rinsing the tomato seeds until they are clean.

Cleaned tomato seeds in sieve

How To Dry Tomato Seeds

When your tomato seeds are clean, tip them onto a dinner plate, and separate the seeds out as best you can. You can then slant the plate to one side to tip any excess water off of it. Then leave the plate with the seeds on it somewhere in the house where they can dry out.

If you have a fan, pointing the fan at the seeds will be very helpful in drying them.

For the drying process, it is often recommended to put the tomato seeds on a paper towel to dry out, but the seeds stick to the paper towel and it can be hard to remove them from it once they dry out. A plate works a lot better.

Tomato seeds drying on a plate

How To Preserve Tomato Seeds

Once the tomato seeds have dried out, place them in a paper envelope, a container or any other way of storing them so they are protected from light, moisture and temperature. Make sure you label the envelope or container with the variety name, harvest date and any other details you’d like to remember in the future. 

Our seed saving envelopes are an ideal storage solution for this. Store the seeds in a cool and dry location to preserve them as best as possible. If tomato seeds are stored correctly, they can remain viable for up to 10 years. 

To preserve tomato seeds for as long as possible, keeping them in the fridge can make them last even longer.

Conclusion

If all of the above steps are followed, you should have an abundance of tomato seeds for planting next year.

Hopefully you might have found this interesting. Maybe it might have opened you up to the art of seed saving. Seed saving can be quite an interesting and rewarding hobby. It can help you to become more self reliant, and to contribute to sustainability by nurturing open pollinated seed varieties. Each saved seed holds the promise of a new season's harvest.

Our full collection of tomato seed varieties is available here.

Sungold Select tomato cut in half, just before seeds are harvested.

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