How to Save Tomato Seeds

Give a friend a tomato and feed them for a salad, but teach them how to save seeds and you feed them for a lifetime.

After talking with a friend who runs their own CSA (Community Supported Agriculture), and realizing that they were not saving their own seeds, I was inspired to write this post. I've been saving my tomato seeds for so many years that I don't even really know when I began. It's fun, actually pretty easy, and is super fulfilling when you sprout new plants from them next spring... and the year after that... and the year after... etc. You gain the power to turn one plant into a thousand plants if you so desired. However, there is a process you must follow- you aren't just scooping out seeds and letting them dry. You actually have to turn it into a wet fermenting science project first, as you will see why.

I hope this information is helpful to you all.

A few notes before we begin: 

When selecting tomatoes for seed saving... you will want to pick the best fruit from the best plant. In this way you are standing in for natural selection to pick what qualities you liked the best. In some cases I pick from the plant that had the least trouble with tomato blight. You might want to favor the most productive plant. Maybe pick the largest fruit from the healthiest plant in general. The idea is that perhaps after so many generations you have selected for a plant that will be ideal for your backyard micro-climate and for your growing needs.

You will want to avoid hybrid varieties. Not that there is essentially anything wrong with them, it's just that they are not going to exhibit as much fidelity as a heirloom variety will (with hybrids it's a gamble of what you might get). Likewise, if you are growing more than one variety of tomato, try to space them away from each other as much as you can. This will help prevent cross pollination and the creation of your own hybrids (unless this is a goal!).

Tomatoes from my friends CSA

1. Choose the best fruit from the best plant.

2. Slice the tomato in half 

(sometimes recommended around the tomatoes 'equator', but this is not essential and may not work with all varieties)

3. Remove seeds and their gelatinous goo with a spoon.

4. Put goo in a container and add a few tablespoons or an inch or two of water.

(a clear glass container works best, I often just use mason jars, but sometimes I use a drinking glass)

goo

goo with water added

5. Cover container with plastic wrap and poke holes in the top for ventilation (this will help fermentation)

poking holes in the plastic wrap

6. Place in a warm sunny windowsill. 

the first day

the second/third day

7. The process should take 2-3 days (though honestly I usually do 4). Each day you will lift the plastic wrap and stir the seed and water mixture.

In the above images you can see how much settling and separation has occurred in a day or two.

8. The top of the mixture will look scummy (it's supposed to, this is fine). The goo is fermenting and the seeds are separating from it all.

I wasn't kidding about the science project part.

9. When complete, spoon/skim off the scum floating on the top. 

There may be some seeds floating at the top with all the scum. There is one thing to remember, the sinkers are the good seeds... any floaters are the bad ones.

yum

10. Pour the container contents into a sieve. Rinse well with water.

This part I find the most satisfying... when you finally get to see what this process was all about- the fermentation completely separates the seeds from everything else.

As Nancy Bubel describes in The New Seed-Starters Handbook:

"Tomato seeds will be protected against bacterial canker if you let the seedy pulp ferment for a few days. The fungi that develop during the fermentation produce antibiotics that control the offending bacteria. In addition, fermentation dissolves the gelatinous coats surrounding the tomato seeds, which contain germination-inhibiting substances." (emphasis my own)

rinse away any remaining goo

11. Line a plate with wax paper or use a Teflon pan surface to spread out the seeds to dry. 

I mean it, spread them out! This is the only easy time to separate the seeds, once they dry they stick to each other like crazy. I have never timed the drying period. I've been using Teflon cookie trays and I will just stick them on a shelf in the pantry... where I basically forget about them. By the time i remember them, they are completely dry and ready to be stored.

spread out to dry and label variety

And for goodness sake, don't make the mistake of not labeling your seeds! I have several heirloom varieties that I grow, and I got really close one year to completely mixing up two totally different varieties of tomatoes. It may be a small point to make, but I don't grow the same number of plants for each variety. I've got it down to a certain number of different heirlooms for eating raw and general cooking and a main emphasis on plum tomatoes for utility reasons in canning. It would be pretty disappointing to mix up those quantities.

San Marzano seeds done drying from a week or so ago

all done

With these simple steps I hope that you will feel emboldened to try it yourself. It really is easy! I found it helpful to write the steps down and stapled them inside one of my favorite gardening books. By next year you may forget part of the process. For storage, I use small envelopes that you can surely purchase at an office supply store. The envelopes are nice to allow them to breathe (these seeds are still alive after all) and you can write directly on the envelop what type of seed and the year it was collected from for reference.

I've been using this method for many years and it's a total success. I was completely sold on the idea of saving seeds after this. I sometimes focus on how fun and amazing this is to do, but it also saves you money on future seed purchases (as with my friend with a CSA, I imagine they spend a good deal more than the typical gardener every year). With the seeds from just a couple tomatoes, you end up with many many times more than you originally started off with in a seed package this past spring. If a friend is growing a variety that you'd like to try, now all you need is just one tomato. Last year I bought a cherry tomato that sounded interesting. I grew it in a container and it was so yummy that I saved it's seeds and grew a whole row of them this year! 

Not only will you have tons of seeds to plant, I've experienced nothing but incredible germination rates. I should do a seed test sometime just to count it, but I'd guess an almost 100% germination rate.

Who knew that such a simple act can feel so empowering. Happy seed saving!