Saving your own seed from vege and flowers in your garden isn’t necessarily difficult – it can save you money, give you good quality seed and be great fun. At WSH we encourage you to do this – not to be completely reliant on the seed companies – it will help ensure that the varieties we sell become more widely grown and that over time they will adapt to the specific conditions in your own garden. All our varieties are ‘open-pollinated’, which means unlike F1 hybrids, anyone can save seed from them and get good results.
If you haven’t done this before, start with an easy crop – peas, tomatoes or French beans –
you will soon see how simple and rewarding it can be!
What to watch out for
Crossing Sometimes two different varieties of the same crop can ‘cross pollinate’ – the
pollen from another variety fertilises the variety you are trying to save for seed. This mean
the seed you get will not be pure – the plants you get when you sow them will be a mix of
the two varieties. Some crops usually ‘self-pollinate’ and rarely cross-pollinate – this helps
make them easy to save for seed.
Unhealthy plants Only save seed from good plants – try to observe them during the
growing season and pull out any sickly ones rather than just collecting seed that happens to be there at the end of the summer.
The weather! To get good seed, it needs to be able to ripen on the plant and you need to be
able to dry it. Crops with a long growing season can be difficult if you live in a colder, wetter
area – you might need to start them early or grown then undercover. NB some crops are
‘biennial’ – that is they don’t produce flowers and seed until their second year – so they
have to overwinter outside or be stored.
Drying and storing your seeds
Dry your seeds in warm (but not hot) airy place. Store them in paper packets in a place
which is as cool and dry as possible – they should be fine for sowing in the next year or two
Don’t put them in airtight plastic bags, boxes or tins unless you have dried them more
thoroughly (using a desiccant such as rice or silica gel) otherwise they may go mouldy.
These are really easy – peas self-pollinate and rarely cross. They are also generally hardy and healthy. Just 3 or4 plants can give you plenty of good seed. If you are growing plants for
eating, start them off early (by mid April) and earmark a few to save for seed at the outset.
Keep an eye on these as they grow and pull up any that are weak or look different to the
others. Leave the pods to fill out, go wrinkly, and ideally brown and brittle on your selected plants if you can – you’ll probably have to pick them in a few batches as they get to this stage, to prevent the first ones from rotting or shedding seeds. If it is the end of the season and the weather turns wet and cold, pull up the whole plants and hang them in an airy shed or greenhouse to dry. Pod the peas out and dry them further if needed – you shouldn’t be able to make an indent on the seed with your finger nail.
Most varieties of tomatoes self-pollinate and rarely cross, and you grow them for seed just
as you would grow them to eat. Make sure the plants of the variety that you are going to
save seed from look healthy throughout the growing season, then pick a few fully ripe fruit – from at least 2-3 healthy plants if you can.
Halve them cross-ways and squeeze out the seeds, goop and juice into an empty jam jar.
You can add a bit of water if you don’t have very much juice. Leave them in a warm place
for 3-4 days – the mixture should start to ferment and mould form on the top. This destroys
the ‘gel’ around each seed.
Fill the jar up with water, put a lid on and give them a shake. Pour off the water, floaty bits
of goop and any seeds that don’t quickly sink to the bottom. Repeat several times until the
water runs clear. Pour the clean seed into a sieve drain thoroughly and spread them out
onto a plate or other shiny surface and dry in an airy place.
French beans usually self-pollinate, but some crossing can happen if different varieties are
grown close together so grow the variety you are saving at least 3m away from others –
further if you are handing it on to a seed swap or seed library. Start the plants early to make
sure the pods have time to mature and dry. Earmark part of a row for seed at the beginning
of the season and make sure these are healthy and none have flowers/foliage different to
the rest. Allow the pods to fill out, turn colour and ideally dry on the plant. Harvest and
process as for peas.
Runner beans are much more likely to cross-pollinate. To get true seed you ideally need to
grow the variety you are saving for seed about 800m from any other variety of runner bean
– although barriers such as tall buildings and hedges which interrupt the flight of insects can shorten the ‘isolation distance’ needed. You need an isolated garden, neighbours that aren’t interested in vege growing or to persuade nearby gardeners to grow the same variety of runner bean!
Otherwise grow and save as for French beans, collecting pods from at least a dozen plants if possible.
Chillies and peppers
Chillies can cross-pollinate with other chillies and also with sweet peppers. You can prevent
this by making sure the variety you are saving is 50m from any other variety, although
barriers such as buildings, hedges (or having them in a greenhouse) can shorten this
‘isolation distance’ needed. Alternatively you can cover a truss of flower buds – or a whole
plant – in insect proof mesh before the flowers open – they will set fruit inside without any
insects or hand pollination. Check during the growing season that all your plants stay
The key to saving the seed successfully is to make sure the fruit are really, really ripe before
you pick them. After that, it’s easy. Cut the peppers open carefully, and rub the seeds
gently off of the ‘core’ onto a plate (wear rubber gloves to deseed chillies) and dry in an airy
Many squash varieties will cross-pollinate not only with each other but with courgettes and
marrows. Unless no other varieties are growing within about 1000m or more, usually the
only way to get pure seed is to pollinate them by hand. The plants have two different types
of flower, male and female. You should be able to see the small immature fruit behind
female flowers. Male flowers just have a straight stem.
Check to make sure all your plants are healthy – in particular remove any with crinkling
mottled leaves as this can be a sigh of virus disease. Go out at dusk and look for both male
and female flowers that are going open the next day – they will still be partly green but
yellow at their tip. Find flowers on 2-3 plants of the same variety if you can. Stop them
opening by gently sealing them at their tip with a piece of masking tape or rubber band. In
the morning, pick a male flower and tear off the petals to expose the central stamen and
pollen. Gently open a female flower (on a different plant if possible), dab pollen onto its
stigma and reseal it straight away – the flower will drop off as the fruit start to develop. Tie
piece of coloured wool or ribbon loosely round the stem of the female flower so you know
which fruits to collect seed from.
Leave your squashes to develop and ripen on the plant for as long as possible – this is well
beyond the edible stage for summer squashes – the skin will change colour and harden.
Once harvested, leave them in a warm dry place for 2-3 weeks to ripen further, then cut
them open carefully, taking care not to nick the seeds. Scoop out the seeds, wash them to
get rid of the fibres, and dry them in an airy place. A dry seed should snap if you try to bend
Cucumbers will cross-pollinate readily with other cucumber varieties, so you need to make
sure there are no other varieties growing within about 1000m (or about half this distance if
they are in a greenhouse). Make sure all the plants are healthy. As with squashes, the plants
have separate male and female flowers, but they are smaller and fiddlier to hand pollinate.
If there are other varieties growing nearby, it is easiest to cover whole plants with a tunnel
of insect-proof mesh or enclose flowers that are about to open in individual bags of mesh
and hand pollinate them as for squashes.
Leave the fruits on the plant until they mature – they will become much fatter, and change
colour (green varieties will turn a dark yellow brownish colour). After harvest, keep the
fruits for a couple of weeks to let the seeds mature fully, then cut them open carefully and
scrape out the seeds and pulp. Clean as for tomatoes.
Lettuce rarely cross-pollinate – if you want to grow two varieties for seed (or other nearby
gardeners have bolting lettuces) make sure they are separated by about 4m. Start the plants off early as they are slow to flower and seed. Select 2 or 3 healthy plants to save for seed – ones that stand without bolting for the longest.
Stake the tall flower stalks as they grow and clear any rotting leaves from the base of the
plant. The seed ripens gradually, starting about 2-3 weeks after the flowers have opened.
Go round every few days and shake the heads into a bucket or paper sack. Sieve to separate the seed from the fluff and husks.
These are perennial, so you can get new plants simply by digging up and dividing established clumps in spring or autumn. However, around mid summer in their second year after sowing, flower heads will also form and these will go on to produce seed. Don’t save seed from any clumps that show signs of disease.
Watch for black seeds forming within the heads as they start to dry – you can shake these
into a paper bag or cut whole heads at this stage and lay them out in a warm airy place to
finish drying and rub the ripe seed out. Remove the chaff by sieving or gentling blowing it