Saving Tomato Seeds and the Tomatoes too

Roma paste tomatoes in mid-August, with stakes flagged for seed collection.
Photo Pam Dawling

August is my busy month for seed harvesting. I alternate tomato seeds and watermelon seeds, getting one batch of each done each week. Today (Tuesday) I packed away a dried batch of Roma tomato seeds and washed 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. I harvested two buckets of Romas on Thursday and left them to fully ripen until today (day 5 for those not counting).

Each year since 2001, I’ve been selecting the Romas for earliness, productivity and resistance or tolerance to Septoria leaf spot disease. In the photo above you can see pink flagging tape on two of the T-posts and yellow on the nearer one. Pink flagging tape marks the plants that had large early yields and OK foliage. Yellow tape marks the plants that have healthier foliage and at least average early yield.

Roma tomatoes getting washed ready for seed extraction.
Photo Pam Dawling

Today I processed the two bucketfuls of Romas from Thursday for seed. I like to do this task on the porch steps as this gives me various heights for the different buckets, and reduces bending double. The next step is to cut each tomato in half lengthwise, pitching any rotten ones in a compost bucket, and putting the good halves in a clean bucket.

Roma tomatoes cut in half for seed extraction.
Photo Pam Dawling

In the photo above, the compost bucket is on the right and the food bucket on the left is getting any edible parts that I don’t want to save seed from for one reason or another. For instance, if the end of the fruit was bad, I don’t want seed from it in case the disease is also in the seeds, but the rest of the fruit is perfectly edible. For the cutting I like a small serrated knife, as shown in the picture.

Roma tomatoes with the seeds removed, all ready for making sauce or salsa.
Photo Pam Dawling

Next I use a soup spoon to scoop out the seeds into a smaller bucket and I put the scooped out halves (“shells”) into another clean bucket. I’ve trained myself to keep moving on this task and only scoop once in each half tomato. I don’t go back for one odd seed that got away!

The “shells” are then all ready for cooking into sauce, or chopping and making into salsa. The seeds bucket gets a loose lid and is put in a cool dark corner of the shed for three days (until Friday). The goal is to ferment the tomato seeds, which kills the spores of some of the diseases, and makes it easier to remove the gel around the seeds and the bits of tomato flesh. I stir once to three times a day to let the carbon dioxide escape, and to break up any surface mold that develops. After three days I wash and dry the seeds.

Roma tomato seeds just after extraction from the tomatoes.
Photo Pam Dawling

I like seed crops where the food part is also harvested (or most of it). Peppers and melons are that way too, but not crops that we eat botanically immature, such as eggplant and cucumber. And obviously not crops where the seed is the food crop, such as peas, beans and corn.

2 thoughts on “Saving Tomato Seeds and the Tomatoes too”

  1. Thanks Pam! We have an incredibly tasty rogue grape tomato of unidentified variety on our farm. I’d like to save the seeds but I wonder if we can get true seed. Could you tell me – what are the cross pollination risks of this plant with our other tomatoes? I suppose it could also be a hybrid, in which case the seed wouldn’t be true either – right? Thanks for your thoughts.
    Amy Wildermann
    Urban Farm Manager
    Richmond, VA

    1. Hi Amy, According to Jeff McCormack who wrote the seed-saving guides for Southern Exposure Seed Exchange: for home use, modern tomato varieties need to be separated by a distance of approximately 10 feet to give a high degree of purity. Older varieties may require a 20 to 25 foot isolation distance. Plants used for stock seed may require an isolation distance of 50 to 150 feet or more in some localities. See It is generally recommended never to save seed from just one plant unless it is the last, only, or second-to-last on the planet. But people do! If your wonderful tomato was in a row with other types, you will likely have some cross-pollination, leading to variable plants next year. But, this could be an educational opportunity! You could save some seed (not just from one fruit, but maybe over a few weeks, collect several. Next year, grow them out and see what happens. Don’t just grow one! You could grow several and plant them much closer than usual, then pull out any you don’t like. Craig LeHoullier in Epic Tomatoes (see my review on writes on how to breed your own tomato variety, which is essentially what you’d be doing, if your plant is chance mutation (“Sport”). He says grow at least 25. My review of this bit is towards the end of my review. Have fun with it! Pam

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