Skip to Content

How to Harvest Tomato Seeds in 5 Easy Steps

If you’re looking for a great way to save money and have bountiful tomato harvests yearly, you should consider harvesting your own tomato seeds. Harvesting tomato seeds isn’t overly complicated as long as you know what you’re doing and take your time. Some of the steps involved may test your patience but having your very own tomato seeds to replant year after year is well worth it. 

How to Harvest Tomato Seeds

If you want to take the next step towards self-sufficiency and learn how to harvest tomato seeds, you’re about to find out how. We’ll go through the process with a step-by-step guide and make sure to explain the benefits of harvesting tomato seeds. 

What Does It Mean to Harvest Tomato Seeds? 

Seeds

Harvesting tomato seeds means you take seeds from tomatoes after they’re full-grown and store them for future use. It’s the same process used by greenhouses and commercial tomato growers. They just do it on a much larger scale. Learning how to harvest tomato seeds for home-growing purposes won’t require you to gather as many, but the process is very similar regardless of the number of seeds you’re harvesting. 

Now that you have a better idea of what it means to harvest tomato seeds, let’s dig into the actual process. 

Choose the Plants You Want to Harvest From

Seedlings

Choosing the right plants to extract seeds from is paramount if you want to learn how to harvest tomato seeds like a pro. Contrary to what you may think, you can’t harvest tomato seeds from just any tomato plant or variety. Heirloom tomato varieties are your best option if you want to grow the same tomatoes year after year. Harvesting seeds from other varieties is possible, but it will likely result in a hybrid plant rather than a pure one. 

In the same way that you can only harvest seeds from certain varieties, you want to be selective about the specific tomatoes you harvest seeds from. For best results with future crops, you should only pick seeds from your vines’ biggest and best tomatoes. These tomatoes likely receive the most nutrients and will contain the best seeds. 

Give Those Plants Extra Care and Attention 

Seedlings

While you want to give all of your tomato plants the attention and nutrition they need to prosper, you should pay extra attention to the plants you plan to harvest seeds from. Here are some general tips and rules for growing superb tomatoes. 

  • Your tomatoes should get an average of eight and ten hours of sunlight per day. 
  • Plant your tomatoes in sandy loam soil for excellent drainage and nutrition. 
  • Choose a fertilizer or plant food explicitly designed to support tomatoes. 
  • Generally, organic fertilizers and soils are best if you want to learn how to harvest tomato seeds for healthy and prolonged use. 
  • Pay attention to the N-P-K ratio on your tomato soil to get the right blend of nitrogen, phosphorous, and potassium. 

When’s the Right Time to Harvest Tomato Seeds? 

Tomatoes with seeds

Knowing when to harvest your seeds is essential in learning how to harvest tomato seeds. Although you can technically harvest your seeds at any point after the plants are fully-developed, you should wait until your tomatoes are full-grown, ripe, and juicy. As such, the best time for harvesting tomato seeds is at the season’s end. 

Because most heirloom tomato varieties take between 70 and 85 days to mature, harvest usually takes place in August or September, depending on when you planted your tomatoes. The nice thing about waiting until the end of the season is that you can use ripe or over-ripe tomatoes. Just because the tomato has gone bad doesn’t mean you can’t harvest the seeds for next year. This is a great way to ensure nothing goes to waste. 

Collecting the Tomato Seeds 

Tomato with seeds

It might go without saying, but the only way to collect your tomato seeds is by cutting them in half and gaining access to the seeds inside. Here’s the step-by-step guide we promised about how to harvest tomato seeds. 

Cut the Tomato 

When following the best method for how to harvest tomato seeds, you should cut your tomato perfectly in half because a bulk of the seeds will be found at the center of the tomato. Unlike other plants, tomato seeds have special sacs of liquid around them that offer protection and nurturing while the tomato is growing. You’ll have to separate the seeds from their sacks to harvest them properly. 

Perform the Fermentation Process 

The best way to ferment tomato seeds is by letting them sit in a tub of tomato juice, preferrable the same tomato you removed them from. In cases where there isn’t enough juice or pulp from the tomato for your seeds to float, you’ll have to add water to the mixture. Give your seeds between two and four days to ferment in this concoction. For best results, allow your seeds to ferment in a dry, warm place in a jar or container. 

Rather than sealing the jar or container, you should cover it with a napkin or paper towel so the seeds can breathe. The cover is so no dirt or debris can get into the storage container. It will also keep the foul odor of the fermentation from cycling throughout your home. You should check the fermentation process at least once daily until you’re sure that fermentation is complete. 

When is Fermentation Finished? 

If you’ve never fermented anything before, it can be tricky because timing is everything with this step of learning how to harvest tomato seeds. You want to wait until you see a thin layer of mold on top of the seeds and the pulp in your container. Eventually, the seeds will sink to the bottom of the jar, and mold and pulp will sit at the top. You should also start seeing bubbles rise to the top of your concoction. 

While you must wait until fermentation is finished, you also don’t want to wait too long. If the fermented seeds are allowed to sit for too long, germination could set in, and your seeds will be ruined. 

Seed Separation 

After fermentation, you’re ready to separate the seeds from the other ingredients in the jar. This process is the easiest step in learning how to harvest tomato seeds. All you need to do is put a lid on the jar, give it a good shaking, and allow everything to loosen up. Next, pour the ingredients of the jar through a strainer so that only the good seeds get caught, and the rest of the contents go down the drain. 

Clean and Dry the Seeds 

Once your seeds are separated from the jar’s contents, it’s time to dry and prepare them for storage. First, leave the seeds in the strainer you just poured them into and hold them under running water for several minutes. You should see residual paste, juice, and mold get washed away. Use your fingers to remove any large or stubborn bits of pulp and debris. 

If you’re satisfied with the cleanliness of your tomato seeds, you can begin the drying process. To do this, pick a warm, dry spot and dump your seeds onto a hard, flat surface such as a glass plate or countertop. Manually separate the seeds from one another so they aren’t touching each other and have room to dry. While it’s tempting to dump the seeds onto a paper towel or napkin to speed up the process, the seeds will stick to them, and you’ll have to start over with rinsing and drying. 

It could take your tomato seeds several days to dry completely. This is where patience comes into play with learning how to harvest tomato seeds because speeding up the process with a blowdryer or heat lamp could kill the seeds. Be patient, and give your seeds as long as they need to dry completely. 

Properly Store the Seeds

After your seeds are nice and dry, you’re ready to store them for future use. You can store tomato seeds in an airtight jar or container and keep them in a cellar, garage, or pantry. The main thing is that they’re in a spot that’s cool, dry, and away from direct sunlight. Properly stored seeds can last for three to ten years. 

Benefits of Harvesting Tomato Seeds 

Tomato seeds

There are many benefits to learning how to harvest tomato seeds, and here are four of the main ones. 

Protect Tomato Species 

Unfortunately, some tomato species are endangered and aren’t readily available at greenhouses or grocery stores. If you’re in love with one of these species and want to ensure that you never run out of them, learning how to harvest tomato seeds is the best way to do this. Harvesting seeds from endangered varieties will allow you to plant them year after year without using a hybrid. 

Saving Money and Hassle 

Tomato seeds certainly aren’t going to break the bank, but they also aren’t free. Learning how to harvest tomato seeds from your plants will save you the cost and hassle of running around town and tracking down a store that sells the seeds you need. Harvesting tomato seeds might be worth it based on the current cost of gas alone! 

Cross-Pollinate 

If you get into learning how to harvest tomato seeds and harvest them from different varieties, you can cross-pollinate during the planting process. You might even invent a whole new tomato species if you’re creative enough. 

Self-Sufficiency 

If your ultimate goal is self-sufficiency and a sustainable lifestyle, learning how to harvest tomato seeds is an important step. It’s also a good stepping stone to learning how to harvest seeds from other fruits and vegetables.

Now You Know How to Harvest Tomato Seeds!

Learning how to harvest tomato seeds is an extremely valuable resource for a home gardener to have. It allows you to maintain a pure line of tomato plants, and lays the groundwork for harvesting seeds from other plants. As previously mentioned, harvesting tomato seeds isn’t overly difficult, as long as you follow the steps in this article and have a little patience. Happy harvesting! 

Looking to learn more about growing tomatoes? Check out our tomato section for growing guides, recipes, and more!