Saving Big Loads of Tomato Seed!

If you grow an open pollinated tomato, it is quite easy to save your own seed. Tomatoes don’t easily cross pollinate so you’re very likely to get what you started with. And you’re harvesting the fruit anyway, so no extra growing procedures.

Tomato seeds are an important seed crop on our farm. Every year, we grow about 5 varieties in bulk quantities for other seed companies. Though, it is quite easy to save seeds from a few tomatoes in a yogourt container, we’ve had to slightly scale up to meet our yield needs …

First, we harvest the fruit:

We then let the tomatoes sit for a few days to a week. As the fruit keeps maturing so does the seed.

Next, we squish that fruit up.

I used to use a well-loved 2×4 for the job.  However this year, our apprentice Heather had a great idea:

Caitlyn demonstrates the new technique.

(Remember to wash those boots before and after each seed lot!)

Nice and squished.

I run the tomatoes through a screen to remove the skins, stems and some of the pulp …

to get a seedy tomato sauce.

Transfer to a well labelled garbage pail.

Let ferment for 2-5 days depending on ambient temperature. I stir each pail a couple of times a day to make sure all the seeds ferment equally. When everything is going right, a thick inch of mould will grow on top of the sauce.

This fermentation is very important:

  • it dissolves the gel sack around the tomato seed that inhibits germination,
  • it controls many bacterial and fungal diseases.

After fermenting, I add water and then decant. The heavy seeds sink to the bottom as I pour off the lighter gunk.

I add more water and repeat. Each time, the water is a bit clearer.

Suddenly, I am left with a pile of clean seeds on the bottom of the can.

I collect the seeds in a colander and then spread them on screens or towels to dry. Or …

I hang them in nylon stockings!

And then direct a fan on the stockings and squish them regularly so they dry out quickly.

It has been a few weeks since my last post but I have sorted out my internet problems so I should be posting regularly again. Coming up soon: first peppers and eggplants and then more on caterpillar tunnels!

10 thoughts on “Saving Big Loads of Tomato Seed!

  1. Great post! I grow heirloom and OP varieties of veggies and have wondered about how small operators can save their seed and sell to companies. Doesn’t seem to be much info about that on the Internet. Could you possibly add a post about how you started selling your seed to companies?

  2. Hi Dan,

    Looks like you might have ‘Roman Candle’ or ‘Banana Legs’ in a couple of them there buckets. I can’t help but wonder about the efficacy of drying those honking masses of seeds in stockings. You have a fan on them, but is the ambient air temperature warm also where they are? I had a fool’s time drying down some suspended bundles of bush beans in unheated sheds recently because of the pervasive moisture in the air. I resorted to bringing them all in to the woodshop and cranking the woodstove along with a couple of fans blowing 24/7. Ah, the vagaries of weather systems.

    1. Who’s got banana legs?
      Indeed, those are banana legs being stomped.

      Brian, good question about the drying efficiency of seeds in stockings.
      My first goal is to remove all the excess moisture from the tomato seed cleaning process. This is done in large part by water dripping from the stockings and good ventilation aiding evaporation. I also regularly (2-4 times a day) squeeze the stockings to break up seed clumps and expose moist areas to ventilation. It usually takes about a day to remove the bulk of this moisture.

      It does take longer to get the seed dry enough for storage. I find that 3-4 days of nice dry weather will get the seed close to the dryness level I want. At that point I bring it indoors to sit close to a wood stove or dehumidifier until I have time to weigh and pack the seeds up.

      To dry down bean plants or other plants, I usually wait until the seed is close to mature in the field and then spread the plants on tarps in the barn or greenhouse. I let the plants dry down for a couple weeks to a couple months. I often increase ventilation by adding fans and I rotate the plants to keep moisture from building up. Things definitely dry down quicker in the greenhouse though.

      When I choose whether to grow a crop or variety, I always consider my prior experience in drying it down. If the crop can’t get to a certain dryness and maturity level in the field then I might not grow it out again.

      This autumn is turning out to be a bit tricky as I wait for that perfect dry week to thresh a number of drying seed piles!
      Later, Dan

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