How To Save Tomato Seeds

Saving seeds from tomatoes is really easy and kind of fun. The process of how to save tomato seeds for next year is not very complicated, but it does involve a couple of steps. Why would you want to save tomato seeds when you can buy tomato plant starts and tomatoes at the local grocery store and farmers market? Simple, really. When you save seeds from a tomato you have grown, you are helping preserve the genetic diversity of tomatoes, and selecting for characteristics that make a tomato better.  To save tomato seeds all you need is an heirloom tomato, a container, a jar in this case, and a few days.

Start by choosing the best tomato on your vine. If it is a slicing tomato cut it in half at its equator.

It is ok if you cut your tomato the other way to expose the seeds inside.

Next, you can squeeze out the inside, seeds, gel, juice and fruit or remove it with a spoon and place it into a container, like a jar, with a wide mouth.

To this mixture of tomato guts, you will add an inch or two of water and loosely close the lid. It may be a good idea to label your container with the name of the heirloom tomato you are saving so you don’t forget later on.

Set this aside for 2-3 days in a warm location outside of direct sunlight. What we are doing here is promoting fermentation that would naturally occur in nature when a tomato falls to the ground and rots. The reason we are fermenting the seeds is that the gelatinous material that surrounds seeds contains inhibitors that prevent the seeds from sprouting inside of the tomato.

As the fermentation process breaks down the gel that coats the seeds it will mold over and look like this.

Once you get to this point, you can scoop out the mold with a spoon. Seeds left in the mixture more than a few days will begin to germinate in the water.  If you use a container that isn't very wide, add more water to the jar and allow the moldy layer to overflow out of the container. This is my favorite part of saving tomato seeds because it is so gross. Pour out as much of the water as you can without spilling any seeds. Slowly Refill the container with water and allow the seeds to settle. Remove any seeds that are floating at this point

Tomato seeds that float are duds. The tomato seeds you want to save are the nice plump seeds sitting at the bottom. Now you can rinse off the seeds one final time to make sure you get as much debris out as possible.

Finally set your seeds out in a plate and spread them out in a warm location to allow them to dry. Make sure to label the plate so you don't mix up the names, if you're doing more than one variety of seeds. It is perfectly fine to use a paper towel or plate to dry your seeds, the only downside of using paper is that your seeds may stick to the surface. Not a big deal, but it can get annoying to peel off dozens or hundreds of tomato seeds.

After your tomato seeds have dried out completely bag them up and save the tomato seeds for planting next year or share them with your friends.  Congratulations, you are now a tomato seed saver.

Choosing a Tomato to Save Seeds From.

Obviously, in order for this to work you have to save seeds from a ripe, open-pollinated heirloom tomato. Tomato seed saving allows you the chance to play plant breeder. If you live in an area with a short growing season save seeds from the tomatoes that ripen first. If you like perfect-looking tomatoes save seeds from the most beautiful tomatoes on your vine. Choose the one with best color, uniformity in shape and size. If size and weight matter most to you save seeds from the biggest, fattest, heaviest tomatoes you grew. If you went on vacation and all of your tomato plants died except for one save seeds from that particular tomato plant. If you grew “Purple Cherokee” tomatoes and one tomato on the vine is a different color, save seeds from that tomato.

When you elect to save seeds from tomatoes with certain characteristics you find desirable you’re creating tomatoes lines that perform the best in your climate or have characteristics that matter to you.

Can I Save Tomato Seeds From the Grocery Store? 

Yes and no. Yes, you can save tomato seeds from the tomatoes in your grocery store, but it is most likely a hybrid and the seeds may not grow a tomato similar to the one you ate.

Can I Save Seeds from Farmers Market Tomatoes? 

If the farmer sold heirloom tomatoes, yes you can save seeds from the tomato at the farmers market. Although, there is a chance the plants cross-pollinated, creating a completely new hybrid. This isn’t a bad thing; it just means that you have a new tomato. If this happened, chances are remote but still a possibility, then the tomatoes you grow from these seeds will be different from the tomato you bought from the farmers market.

Saving heirloom tomato seeds is fun, rewarding and can save you money on your seed purchases. It also allows you to exercise your inner plant nerd, play tomato breeder, and really make you think about what makes that particular heirloom tomato so great. Inside of each of those tomato seeds is the story of your summer of tomato growing. The best thing to do with these tomato seeds is to put some away to plant next year and repeat this process every year. Share the rest of your saved tomato seeds with friends and family. After all, what good is it to have an heirloom if there is nobody to pass it down to?

If you're new to gardening check out my post on How to Save Seeds and How to Store Seeds. Interested in growing some of your own food? See my post on growing potatoes in a bucket and how to pollinate strawberry flowers.