How to Save Tomato Seeds Without Giving up the Tomatoes

Reader Contribution by Pam Dawling
article image

Roma tomatoes with stakes flagged by the best plants.  

I alternate processing tomato seeds and watermelon seeds, getting one batch of each done each week, from late July to the end of September. I keep my drying area in constant use: the day I pack away a batch of dried Roma paste tomato seeds is the day I wash and set to dry a batch of Crimson Sweet watermelon seeds. These are both the Virginia Select strains which I sell to Southern Exposure Seed Exchange. Each year since 2001, I’ve been selecting tomatoes for high yield, earliness, and resistance or tolerance to Septoria leaf spot disease. I use pink flagging tape on the T-posts to mark plants with large early yields and OK foliage, and yellow tape to mark plants that have healthier foliage and at least an OK early yield. By saving tomato seed for next year, you can keep heirloom and heritage tomato varieties alive, and over time, you can improve the variety to suit your region.

I wrote about saving tomato seeds and eating the tomatoes too on my blog at This year I decided to harvest tomato seeds on Thursdays and leave them to fully ripen until Tuesday (5 days), when I processed them for seed. I washed them and cut each tomato in half, dropping any rotten ones in a compost bucket, and putting the good halves in a clean bucket. I like a small serrated knife for this task.

Roma tomato shells seeds removed  

How to Remove Seeds from Tomatoes

Next I scoop out the seeds into a smaller bucket using a soup spoon. I put the scooped out halves into another clean bucket ready for chopping and making into sauce or salsa. I put a loose lid on the seeds bucket and set it in a cool dark corner of the shed for 3 days (until Friday). This is long enough to ferment tomato seeds, which kills the spores of some of the tomato diseases, and also loosens the gel around the seeds and any bits of fruit. I stir at least once a day to break up any surface mold and release the carbon dioxide.

Roma tomato seeds 2 day.

Washing and Drying Tomato Seeds

After three days (Tuesday to Friday this year) I wash and dry the seeds. They look unattractive at first, because of a thin layer of mold on the surface. Washing the seeds and pouring off the junk is almost magical. If you dry tomato seeds without fermenting, they all stick together, so I definitely recommend fermenting.

I do a series of about four washes, floating off more of the tomato flesh each time, along with poor quality seeds. I add water from a hose until the bucket is about two-thirds full and I stir the mixture. Then I let the liquid settle, with the good seed sinking to the bottom of the bucket. Next I pour the liquid along with bits of fermented tomato into another bucket, then dump that. This is a precaution to ensure I don’t slip and throw away good seed. I repeat the wash and pour a few more times. After just the second pour the treasured seeds are plain to see.

Seeds that float are poor quality – let them go! They are either very thin or they have a black spot in the center. So it’s counter-productive to try to catch every single seed.

After four or five washes, when the water I pour off is clear, I add more water, stir and pour the contents of the bucket through a sieve into a bucket.

Wet Roma tomato seeds and fan.

Next I take the sieve indoors and empty it on sturdy paper towels on a tray in front of a small fan. I come back after a few hours to crumble up the clumps of seeds and even out the drying. I turn the seeds over a few times a day for a couple of days. Once they are dry I put them in a labelled paper bag, and prepare the space for the next batch of wet seeds. Watermelon in my case.

Seed saving is very rewarding, and with tomatoes you can not only save seeds for planting, but at the same time, prepare the tomatoes for canning or juicing.

Pam Dawling works in the vegetable gardens at Twin Oaks Community in central Virginia. She often presents workshops at MEN Fairs. Pam also writes for Growing for Market magazine. Her book, Sustainable Market Farming: Intensive Vegetable Production on a Few Acres, is available, Pam’s blog is on her website and also

All MOTHER EARTH NEWS community bloggers have agreed to follow our Blogging Guidelines, and they are responsible for the accuracy of their posts. To learn more about the author of this post, click on their byline link at the top of the page.