Tomatoes can be grown quite easily from seed, and you can use seeds collected from tomatoes you’ve grown yourself, or from ones you’ve purchase from the greengrocer!
There are a few tricks to saving tomato seeds, as they are wet seeded crops, which have seeds embedded in the damp flesh of fruits. When tomato seeds are cleaned and dried correctly, they can be stored in a cool, dry place for up to 5 years or longer.
Only two vegetable plant families have wet-seeded fruits, the Solanaceae family, which includes tomatoes, capsicums, eggplants, and the Cucurbitaceae family, which includes cucumbers, melons, squashes.
Which Tomatoes to Use for Seed Saving
Always leave the earliest and biggest tomato fruit, or most productive and strongest plants of the season for seed collection. Resist the temptation to eat the first tomatoes!
To mark which tomatoes were produced first, you can loosely tie a piece of string, wire twist tie or other material that is coloured and stands out. Tie it above the cluster of fruit, or around the stem of the plant.
The great thing about seed saving and growing from your own seeds is that each generation of tomatoes will become, bigger, more productive, and better suited to the local conditions.
The most reliable tomato varieties to use for seed saving are:
- Heirloom varieties, these are open pollinated (non-hybrid) tomato cultivars (cultivated varieties or breeds) that are over 50 years old and have been preserved through generations by careful seed saving.
- Varieties that are known to grow and produce well in your local area.
Which Tomatoes You Should NOT Use for Seed Saving
Never collect seeds produced from F1-hybrid plants. An F1 hybrid is the first generation offspring from a deliberate cross-pollination of two specific parent plant varieties. The seeds will not produce the same plant as the parent plant!
When you buy a packet of seeds, or a punnet of seedlings (small plants), the label will indicate if the tomato variety is an F1 hybrid. Since you can’t save the seeds of F1 hybrid plants, because they are not true-to-seed, skip them and select a more useful variety.
If you buy organic tomatoes from the greengrocer, they will be open-pollinated varieties and not hybrids. So, if you purchase some, and like their flavour, save their seeds and plant them up in spring!
How to Save Tomato Seeds
Tomatoes are wet seeded crops, which have seeds embedded in their damp flesh, so we need to use the process of rinsing to separate the seeds from the pulp when saving tomato seeds.
To rinse tomato seeds:
Step 1. Cut the tomato in half lengthwise.
Step 2. Scoop out the seeds and pulp into a strainer.
Step 3. Put the strainer under moderately pressurised running water.
Step 4. While under running water, rub the contents of the strainer with your fingers, and rinse until the seeds are clean and free of pulp.
Once the seeds have been rinsed free of the pulp, they next step in the seed-saving process is drying.
Step 5. Dry seeds the seeds by placing the strainer in a location with good air circulation, so they can dry as quickly as possible, to reduce the risk of disease, or the seeds getting mouldy.
A convenient location for seed drying is the kitchen windowsill, as shown below. Ideally the position should be warm, but not too warm, and not in hot, direct sun as excess heat can damage the seeds.
Sitting the strainer with seeds on a paper towel for a few minutes first, to soak up the excess water, speeds up drying time considerably.
Other drying methods include spreading a very thin layer of seeds onto a wire screen, a piece of wood, a pan or tray, or any hard, non-stick surface, including the strainer used in the rinsing process.
Keep in mind that seeds will stick badly to paper towels, cardboard, newspaper or cloth if it’s used as a drying surface.
Step 6. Leave the seeds to dry for a few days.
Step 7. Place the dried seeds in a suitable container or envelope, and label it. Include plant name, variety, date collected (and use-by) on the label.
Labelled envelopes of seeds can be placed inside sturdier containers to better protect them. Place envelopes or containers of seed in a cool, dry place to ensure maximum seed storage life.