If you've grown tomatoes this year, don't throw away the seeds. Late summer and early autumn is the ideal time to save them for next year, helping you get even more from your harvest and cut the cost of buying fresh seed packets each spring.
It’s also one of the most budget-friendly gardening jobs to tackle in September. Here are five simple steps to save tomato seeds for next year's crop.
1. Choose healthy, ripe tomatoes
The first step is choosing the right tomatoes to collect seeds from. Select a fully ripe tomato from a plant that has grown well throughout the season.
‘Select a few healthy tomatoes, and pick these off the plant when they are very ripe,’ says Richard Barker, horticultural expert and commercial director of LBS Horticulture.
Avoid tomatoes showing signs of disease or damage, as you want to start with the strongest possible seeds. If you particularly enjoyed the flavour, size or appearance of a tomato plant this year, it’s a good candidate for saving seeds.
2. Scoop out the seeds
Once you've chosen your tomato, cut it in half and scoop out the seeds and surrounding gel into a clean container.
‘Cut the tomatoes in half, and use a teaspoon to scoop out the seeds into a shallow jar of water,’ explains Richard.
Don't worry if there is still some tomato flesh attached – this can be removed during the cleaning process.
It's worth saving seeds from more than one tomato if you have several plants of the same variety. This gives you a larger selection of seeds to sow next year and increases your chance of successful germination.
3. Ferment the seeds
Fermenting the seeds helps remove the gel coating around them, which can contain compounds that inhibit germination.
‘Set the jar aside for four or five days, during which a mould will develop,’ explains Richard. ‘This mould is not something to be concerned about, as it will help to remove the gelatinous coating on the seeds that prevents them germinating.’
After four or five days, add more water to the jar and gently stir the mixture. The healthy seeds should sink to the bottom, while some of the unwanted material will float to the surface.
4. Rinse and dry the seeds thoroughly
Once the seeds have fermented, carefully pour away the water, then rinse them several times with clean water.
‘Place the seeds on a piece of kitchen roll to dry out, and once they have dried out thoroughly they can be stored,’ Richard tells us.
This may take several days, so don’t rush the process. Any remaining moisture can encourage mould to develop during storage. Make sure the seeds are completely dry before moving on to the final step.
5. Store them somewhere cool and dry
Once your tomato seeds are dry, place them in a labelled paper envelope or airtight container. Make sure you write down the tomato variety and the year they were collected so you know exactly what you're planting when spring arrives.
‘After this, keep it in a dark drawer so you're all ready for next season,’ says Dean Commodore, gardening expert and founder of DIY Dad.
When it’s time to sow them next year, simply take out your saved seeds and start growing again.
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