Search

Urban Food Garden

Saving Tomato Seeds

As tomato plants do not cross pollinate seeds collected from tomatoes will stay true to type, which makes them an ideal vegetable from which to save seeds.   This page gives details on three methods of saving tomato seeds.

Selecting the tomatoes to save seeds from

CLEARLY LABEL THE TOMATO PLANTS THAT YOU WISH TO TAKE SEEDS FROM AT THE START OF THE SEASON
This is so you do not mislabel your tomatoes when harvesting your seeds.  Many tomato varieties produce tomatoes that look similar to other varieties.  

PICK THREE OR FOUR TOMATOES FROM THE EARLY SEASON CROP
This is because the older tomato plants are the more likely it is to be infected by soil-borne diseases, which can be passed on via the seeds.  Do not pick any tomatoes from sickly looking plants (leaves with brown or yellow edges) as they may be diseased.  

Note that such diseases are not directly passed on to the seed but are in the gelatinous sac that tomato seeds are encased in.  It is possible to separate the seeds from these sacs (see details below) but it is much better to use tomatoes from plants that do not show signs of disease.

Saving the seeds

There are three methods to save tomato seeds that I have used, details of which plus a comparison of their various pros and cons are listed below.

The smear method

This involves smearing the seed encased pulp onto a sheet of paper and leaving the pulp to dry.   When the seeds are needed  they are scraped off the paper for planting in a seedling box.

A sheet of paper with fresh tomato pulp smeared on it.

The same sheet of paper after the pulp has dried.

ADVANTAGES SUMMARY
(flip me)
ADVANTAGES
  • Involves little time to save the seeds.
  • Is a single stage method, the two other methods involve multiple stages.
DISADVANTAGES SUMMARY
(flip me)
DISADVANTAGES
  • Awkward way to store seeds.
  • Does not separate the seeds from the gelatinous sac they are encased in (increased disease potential).
  • Can be difficult to separate each individual seed attached to the paper.
The water pressure method

This method involves blasting the gelatinous sacs from the seeds using water pressure, it is not as effective at removing the sacs as the Fermentation Method but is much quicker.  It is the method I prefer to use.

1. SELECT RIPE TOMATOES FROM AT LEAST TWO OR THREE PLANTS AND CUT INTO QUARTERS
The tomatoes should be ripe but not over ripe.  If saving cherry tomatoes just cut them in half.

2. WASH THE SEEDS INTO A SIEVE UNDER A GENTLY FLOWING TAP
Manipulate the pulp with your fingers to help remove the seeds, picking out any large pieces of pulp that fall into the sieve. 

Save the quarters after the seeds have been washed out for cooking or freezing for future food use.

3. WASH THE SEEDS WITH A JET SPRAY UNTIL ALL THE JELLY SURROUNDING THE SEEDS HAS BEEN WASHED AWAY
This usually takes one to two minutes.

4. TAMP THE BOTTOM OF THE SIEVE ON SOME PAPER TOWEL TO ABSORB ANY EXCESS WATER.
This might have to be done two or three times using fresh paper towel.

5. UP END THE SIEVE ONTO A SHEET OF PAPER AND LEAVE TO DRY AWAY FROM DIRECT SUNLIGHT
Once dry the seeds can be bagged and labelled.

ADVANTAGES SUMMARY
(flip me)
ADVANTAGES
  • The process takes less time and effort than the Fermentation Method.
  • Removes the gelatinous sacs, which means the seeds will not stick together when dried.
DISADVANTAGES SUMMARY
(flip me)
DISADVANTAGES
  • Not as effective at removing the gelatinous sac as the Fermentation Method.
  • Involves more time and effort to process the seeds than the Simple Drying Method.
The fermentation method

The seeds in tomatoes are encased in gelatinous sacs, it is there to stop the seed germinating in the mainly liquid pulp that surrounds it.  The fermentation method is used to dissolve these gelatinous sacs from the seeds before they are dried.  

  1. SQUEEZE THE SEED LADEN PULP INTO A JAR, ADD SOME WATER AND LEAVE  AT ROOM TEMPERATURE FOR ABOUT TWO OR THREE DAYS
    Adding water starts a fermentation process that breaks down the gelatinous sacks surrounding the seeds.  It is important that you leave the seeds fermenting for no longer than necessary as once the gelatinous sacs have completely dissolved the seeds will begin to sprout, making them useless for seed saving.  Mold may form on the surface of the water, but this is not a problem.

  2.  AS SOON AS THE GELATINOUS SACKS HAVE DISSOLVED  TIP THE CONTENTS OF THE JAR INTO A FINE SIEVE AND RINSE WITH RUNNING WATER UNTIL ONLY THE SEEDS ARE LEFT

  3. TAMP THE BOTTOM OF THE SIEVE ON SOME PAPER TOWEL TO ABSORB ANY EXCESS WATER
    This might have to be done two or three times using fresh paper towel.

  4. ONCE THE SEEDS ARE COMPLETELY DRY SCRAPE THEM OFF THE PAPER, PLACE THEM IN AN ENVELOPE OR AIRTIGHT CONTAINER
    Make sure you label the seeds, it is also a good idea to add a use by date.

LEFT: Squeezing the seed laden pulp into a glass.  RIGHT: Adding water.  The amount of water added will vary depending on the amount of pulp, normally I would add a 50/50 ratio by volume.

ADVANTAGES SUMMARY
(flip me)
ADVANTAGES
  • Most effective way to remove the gelatinous sacks around the seeds.
  • Involves less rinsing than the Water Pressure Method.
DISADVANTAGES SUMMARY
(flip me)
DISADVANTAGES
  • If the seeds are left too long to ferment they will begin to sprout.
  • Is the most complex and time consuming of the three tomato seed saving methods.

RELATED POSTS