Right about now is one of my favourite times in the garden. It may not be at its ‘prettiest’ anymore in the eyes of some but I behold things with a slightly different focus. Not only is there plenty of food to be cropping but there are also plenty of seeds to collect. Free seed this year = free plants and food next year. Now that’s a punk rock result!
Pretty much all of the flowers and veg I grow in the garden produce viable seed. This is the big advantage when you choose to grow seeds from pure lines rather than hybrids. Saving seed from hybrid species is pretty pointless, especially if you don’t have much space, as none of the offspring will have stable genetics and you will end up with all manner of shapes, sizes, colours and/or flavours (good and bad) depending on what you’re growing. So stick to the non-hybrid varieties if you don’t want to have to keep buying the F1 seeds every year.
Also, it pays to remember that many varieties will also readily cross-pollinate with others of their kind. This isn’t anywhere near as problematic as F1s crossing, especially if they’re high quality pure lines getting jiggy with each other. But if you want to keep a particular variety of these types true to the parent plant, either stick to only growing that specific variety or keep the different varieties isolated from each other. How (or even whether it’s practical) to do this depends on how they are pollinated. Chillis, for example, are pollinated by insects moving from flower to flower. So, if you want to grow two types, a net cage moved from one type to the next on alternate days will allow insect pollination while preventing cross-pollination. Complete isolation is the only really guaranteed way of keeping things perfect but I don’t require or desire absolute perfection (most of the time!), so close enough is good enough for me.
That’s enough theory, time to get on with the fun bit.
Saving seed is easy, needs no special equipment, and requires just a bit of your time (and a nice cup of tea to help you along).
Firstly, you can (and should) choose the best plants as your seed source. When you sow them next year, you’ll be guaranteed to have great results.
Then you find out the best time and way to collect the seed. For flowers, it’s normally just a case of leaving the flowerheads to die and literally go to seed. These seedheads will then ripen, which usually means that the seeds fall freely from the plant if you give ’em a shake or gently rub the seedhead. That’s the perfect time to collect ’em. Make sure you do this around noon or early afternoon on a dry day, not just because it’s more pleasant for you but because it means the seed isn’t damp.
Collecting veg seeds is slightly different but, almost without exception, is best done when the vegetable itself has fully ripened and matured. There’s a good introduction to veg seed saving here and here. Google should help fill in the gaps.
Once you’ve got your seed, you may have a couple of options of what to do with it depending on the species. Seed from many native plants in the UK (as well as non-natives from the same hardiness zones) can be sown as soon as they’re collected. In some species, they’ll germinate straight away. The plants then have enough time to put on a decent amount of growth before the approaching rigours of winter set in, and they’ll have a great head start come next spring. This is particularly useful for biennials like foxgloves, as they’ll produce flowers in the same year. Other species need a period of cold to break their dormancy (known as cold stratification) before they’ll spring to life, so sticking ’em in a pot, bed or seedtray in the garden now will ensure they get the chilling they need once the snows and frosts take hold (an alternative is to reproduce the same effect in your fridge before next spring – mix the seed with some damp vermiculite, seed compost or sand in a ziplock baggie, remove most of the air, seal and put in the salad drawer of your fridge for however long the species needs).
The rest of your seeds, including most of your veg, will need to be kept until next spring or beyond. That’s easy enough too. You need to make sure the seeds are properly dry. Seeds from ripe flowers will probably not need any further drying, seeds from veg will almost certainly need a bit of help. Just put them in a warm and dark place with decent air circulation and low humidity until they are. The seeds can then be stored in paper envelopes or bags in an airtight container in the fridge. Seeds will often remain viable for quite a few years like this, although germination rates will eventually decline over time. For even longer-term storage, many seeds will also survive quite happily in the freezer.
Chances are you’ll end up with more seed than you need. What a great problem to have, eh? Either swap or give them away (via friends, the web or by organising a community seed swap) or indulge in a spot of guerrilla gardening.
So that’s the basics. The specifics are down to you, your plants, your tea supply and Mr Google.