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This year we have been showcasing tomato diversity at Global Gardens. We have been cultivating eight different tomato varieties in the Global Gardens polytunnel:

Ailsa Craig

Black Cherry

Bloody Butcher

Gardener’s Delight

Golden Sunrise

Miele de Mexique

Noire de Crimée

Pink Georgian

On the 30th September, as part of the Food Cardiff #GoodFoodCardiff Autumn Festival, we celebrated tomato diversity with a range of activities including a tomato taste trial, tomato cooking and seed-saving. In this blog, Poppy shares her approach to tomato seed-saving…

Step 1. Select your tomatoes.

To begin seed-saving your tomatoes, pick some tasty-looking, fully ripe fruit from the selected variety. Consider fruit size - opt for an average size rather than a small or large one - unless you would like to try to select for size. Ensure the plant is looking healthy and disease-free. Some people save the first truss of the tomato plant since disease is less-likely at the start of the season.

Step 2. Gather your tomato seed.

Slice your selected tomatoes and squeeze the seed into a jar. Depending on how juicy the tomato is, you may want to add some more water so the seeds are floating freely in water. It doesn’t need to be much water, just enough for all of the seeds to be fully submerged. Ensure the jar is labelled with the tomato variety. Tomato seeds have a coating which inhibits germination. To break this down, seed-savers tend to use the fermentation method.

Step 3. Leave the seeds to ferment in their own juice.

Cover the jar with a muslin cloth for 2-3 days on a windowsill.

Step 4. Process the seed.

You will know when the tomato seeds are ready for processing when they have a slight white dusting of mould on the surface and they smell a bit fermented. Once the tomatoes appear suitably fermented, rinse them. You can do this in several stages, pouring half a glass of water and draining off until you reach the seeds. Repeat until all of the flesh is removed and you only see tomato seeds. Pour the mix into a sieve and tap the sieve upside down on to a piece of cardboard. Use the back of a sieve to spread the seed out so the layer is only one seed thick. Make sure you label the cardboard with the variety.

Step 5. Dry the seed.

Leave to dry in an airy spot away from direct sunlight for a few days.

Step 6. Store the seed.

You can then safely store your seed in an envelope in a cool, dry space away from sunlight. Don’t forget to label the envelope with the variety name!

To find out more about saving tomato seeds, check out this excellent guide by the Heritage Seed Library.

Thanks to Food Cardiff for supporting the seed-saving activities at Global Gardens. Poppy would like to thank the UK & Ireland Seed Sovereignty programme for supporting the development of her seed-saving skills. They host a range of seed-saving activities and a bi-annual seed-saving festival.


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