Saving Tomato Seeds September 07, 2013 12:37 2 Comments

A few years ago I was a volunteer with the Vancouver Farmer's Market.  When the market held its annual Tomato Festival, I manned the sampling table where customers could see and taste some of the more unusual tomato varieties sold by market vendors.  The most frequently asked question was whether the farmers growing these heirloom tomatoes also sold seeds; people wanted to be able to grow these unusual tomatoes themselves.  Unfortunately, the answer was 'no' and many people were disappointed.
 Their fleshiness makes the German Red Strawberry a great eating and cooking tomato.
 Their fleshiness makes the German Red Strawberry a great eating and cooking tomato.

I was disappointed, too, because I had found an heirloom tomato variety that I really liked--the German Red Strawberry, which is large, pink and meaty, everything I ever wanted a tomato to be... and the flavor is delicious!   After four hours of slicing tomatoes and clearing my cutting board of gelatinous goo and seeds, it dawned on me that every tomato contains the seeds for growing more tomatoes like itself!  It sounds so obvious, but as a newbie gardener, I was used to buying seeds in a little paper envelope with detailed instructions.  Some seeds, like beans or peas, come out of their pods looking just like they would from a seed packet, but seeds straight out of a tomato are anything but clean and dry. Obviously there was some process required to save tomato seeds.  When I got home from the market that day, I decided to find out what that process was.  It turned out it was quite simple and when I worked the tomato booth at the next market, I shared what I'd learned with anyone who asked.  Then, I took my own advice: before leaving the market that day, I purchased several of the meatiest German Red Strawberry tomatoes I could find and I took them home to save their seeds.  That was five years ago and I have planted this unique variety of tomato every year since then and it is still my favorite tomato.

So, here's how you do it: 1. When choosing tomatoes to save seeds from, consider that you are selecting the genetic traits of your future tomato crop, so select fruits that are a good representation of the variety you've chosen.  Or, select fruits that display traits you are looking for in regards to size, color and disease resistance.

 If you're careful not to mangle your tomatoes when scooping out the seeds, you can still eat them for dinner. 
If you're careful not to mangle your tomatoes when scooping out the seeds, you can still eat them for dinner.

2. Cut each fruit in half across its middle and carefully scoop the seeds and goo into a jar or small dish.  I use the tip of my knife to do this.  If you're saving seeds from more than one variety, be sure to label your jars!

 Tomato seeds with germination-inhibiting goo.
Tomato seeds with germination-inhibiting goo.

3. If you don't have much goo in your jar, add a splash of water so the moisture won't evaporate during the next step, leaving you with a dried-out, stuck-on mess.

4. Cover the jar with a clean cloth and let it sit out at room temperature for 2-3 days, or until it smells like rotten tomatoes.  I know it's gross, so maybe find an out-of-the-way spot where the smell won't be too offensive, but the goo needs to ferment to come cleanly away from the seeds.  (Technically, the "goo" is a growth inhibitor, which keeps the seeds from germinating inside the tomato.)

 This tomato goo is broken down and ready to be rinsed.  Be glad you can't smell this!
This tomato goo is broken down and ready to be rinsed. Be glad you can't smell this!

Do not let your seeds soak in this mixture for more than 4 or 5 days or else they will start to germinate and it will be too late to dry and save them.

5. Once the goo has broken down, it's time to rinse your seeds.  Add some water to the jar and swirl it around gently.

 Viable seeds sink; duds and debris are rinsed away.
 Viable seeds sink; duds and debris are rinsed away.

Viable seeds will quickly settle to the bottom; duds and debris will float and can be poured off with the excess water.  Repeat this step a few times until no debris remains and the water pours off clear.

 These seeds are clean, dry and ready for storage.
These seeds are clean, dry and ready for storage.

6. Lay the seeds out on a paper plate or saucer lined with a paper towel.  After a day or two, separate any clumps of seeds by rubbing them between your fingers and allow to dry for another day or two.

7. Store clean, dry seeds in an air-tight container in a cool, dark place.  Be sure to label the container.  In addition to the variety name, record the year in which the seeds were saved as well as any notes that might be useful in the future (bush vs. vine, early vs. late, etc.).  Tomato seeds are viable for 3-5 years or more, with a declining germination rate after that.