Saving seeds from your garden is more satisfying than buying them in packets. Here’s how to do it
As summer gives way to autumn, it’s a good time to think about gathering seeds from the year’s final harvest. If all goes well, you’ll be left with ones from your favourite crops in greater abundance than if you had bought them in a packet.
The way to collect tomato seeds is to scoop the insides out of ripe fruit – the seeds and all the gloop. Place it all into a jar with a little water then put the lid on and give the mixture a good shake. Leave this concoction to ferment for a few days to remove the germination inhibitor found in the juice around the seeds. Any unviable seeds will float to the top – where they can be scooped off – leaving the good stuff at the bottom of the jar. Give the viable seeds a gentle rinse in a sieve and leave them to dry completely on a piece of kitchen roll before storing them in a labelled envelope.
Beans – along with peas, the saving of whose seeds I wrote about last spring – produce perfect flowers that are capable of self-pollination, so they make a good candidate for at-home seed-saving. Leave the beans on the vine until the seeds have swollen and the pods have become dry and leathery. Ideally, this will happen while the pods are still on the plant, but if heavy rain is forecast, it’s best to pick them early and leave them to finish drying indoors before harvesting and storing their seed.
Parsnip seeds have short viability and are best sown by the following season; whereas plenty of familiar crops – including beetroot and lettuce – can last for five years
If you take on the challenge of saving seeds from courgettes and cucumbers, you have to leave the fruit until it goes beyond its edible stage. Once it has developed a tough outer skin and turned a slightly unattractive yellow, harvest the fruit and leave it for about a week to let the seeds fully mature. Scoop the seeds into a jar and follow the tomato seed fermentation method detailed earlier, ensuring the seeds are entirely dry before storing.
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The viability of saved seeds varies widely. Certain seeds, if stored correctly, can still germinate after being stored for several years. Parsnips and agretti are examples of seeds with short viability, best sown by the following season, but plenty of familiar crops – including beetroot, coriander, lettuce, fennel and dill – can last for five years or more. Incredibly, lotus seeds that were nearly 500 years old were successfully germinated by scientists from UCLA.
The key to good seed viability is making a careful plan for storing them. They will remain dormant if kept in the opposite conditions to those they need to germinate. Since most seeds need warm, moist conditions to sprout, keep them somewhere cool and dry – the RHS recommends a sealed airtight container – and don’t move them. Time spent in less than ideal conditions will chip away at their viability. Good luck!
