Save your own seeds

Saving your own seed from veg 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.

Seed-saving guidelines

French beans
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
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 veg 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.

Squash
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 it.

Lettuce
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.

Welsh onions
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 off.

Brassicas
These plants are biennials and include kale, broccoli, cauliflower, sprouts and cabbage as well as Chinese and Japanese greens. This family of vegetables is very promiscuous and is likely to cross pollinate so only let one variety flower.  Start by growing your crop as for eating, but at the end of the year carefully look at your plants and select the most typical disease-free plants to save your seed from. Select at least 20 plants to grow on and flower as the brassicas are outbreeders and need to cross pollinate within a group of plants. As the seeds start to form you will need to decide when to harvest them because if they are not mature enough (still green) they will not germinate well and if you leave them too long (brown and ripe) they are likely to shatter and you will loose the seed. A good choice is when the seeds are round and full and some of the seeds are going brown. Look at the pods in the middle of the flowerheads when the lower pods are starting to shatter and the upper pods are filled. Take seedheads from every plant to ensure genetic diversity. Spread the seedheads out in an airy warm shaded place to completely dry and then take an old sheet or tub trug and put the seedheads on it before stomping on them. Put the resulting mix in a tub trug and give it a good shake so the seed falls to the bottom and then lift of most of the broken pods. Clean the seeds with sieves and a zig zag cleaner if you have one and don’t forget to label them.. Store the seeds with silica gel in a cool dark place for the longest shelf life. Brassica seed stores well and will last at least 5 years so you can grow a different crop for seed each year.

Flowers
Half hardy annuals 
Frost tender flowers are a huge group of plants which have slightly different growing habits and requirements for seed saving. So here are some general rules for seed saving.

Wait for the seed pods to ripen and change colour but before they fully split and scatter their seeds. Only collect the seeds from strong healthy plants, and ensure that you save from the widest range of colours. Collect seeds on a dry sunny day after the dew has evaporated. Cut the seedheads or stems and dry in a warm airy place away from direct sunlight. Once they are completely dry then crush the capsules/pods to release the seeds or shake the seeds into a paper bags. Clean the seeds with sieves and a zig zag cleaner if you have one. Store the seeds with silica gel in a cool dark place for the longest shelf life and don’t forget to label them.

Hardy annuals
This group of plants often self-seed so you can let them drop their seeds  around where they are growing. If you want to grow them in a different area of the garden, then cut the stems when the seed pods first start to drop their seeds in the middle of a dry day. Put the stems head down in a large paper bag and don’t forget to label it. Hang the bag in a warm dry place out of direct sun, until the seeds fall into the bottom of the bag, then take the seeds and store them with silica gel in a cool dark place for the longest shelf life and don’t forget to label them.

Summary

A word on isolation distances, Isolation distances operate on a spectrum of plant “promiscuity,” ranging from close (a few meters, for self-pollinators like peas that keep to themselves), to medium (~50m for “opportunistic” crossers like peppers), to far (~800m+ for obligate cross-pollinators like squash and brassicas that actively seek out neighbours). It is important to remember, however, that these distances are not an exact science; they are more like best-practice” estimates. Real-world variables such as the density of your local bee population, prevailing wind patterns, or even a tall hedge acting as a flight barrier can drastically change how likely a cross-pollination event is to occur. If you find that the required 800 meter gap is a logistical fantasy in your neighbourhood, you can bypass geography entirely through mechanical isolation. Utilising fine-mesh nets, isolation cages, blossom bags, or even taping flowers shut for hand-pollination allows you to create a “physical” distance that is just as effective as a half-mile of open space.