Seed Saving for Home Gardeners
Notes prepared by Kat Lavers, 2025
Seeds are embryonic plants, alive yet dormant, awaiting the perfect conditions to grow. Some are tiny and brown to camouflage from animals, some only germinate when scorched by fire that has cleared the canopy and laid a fertile bed of ashes, while others are brightly coloured and encased by enticing fruits to attract a creature (like you!) to eat and disperse the seed.
With a few simple seed saving techniques, you’ll grow stronger plants than you could ever buy and crop yields will improve. You’ll save money and have an abundance to share with family, friends and neighbours.

Seeds are our past, our present and our future. We’re at risk of losing thousands of open-pollinated heirloom seed varieties because they’re not commercially valuable, and yet it’s from this vast agricultural biodiversity that resilient varieties will be selected and bred to adapt our food systems to a changing climate. By saving seeds at home you are stewarding the seed heritage passed down by our gardening and farming ancestors. Over time you can even breed new varieties with spectacular colours, shapes and flavours that are uniquely adapted to your local conditions.
Will you be a seed steward?
Choose an heirloom variety, save seed every year and share it freely in your community. Standing by one seed each is all it will take to protect our seed heritage for the next generation
Some plants are usually propagated by other methods
Sometimes it’s easier to propagate from a piece of a plant, and this ensures the offspring will be genetically identical and have the same characteristics as their parent. Common edible plant examples are potatoes (from tubers), garlic (from cloves) and many fruit trees (from cuttings). Small potato tubers for planting may be labelled as ‘seed potatoes’ in nurseries but this is not true seed.
Seed terminology
Hybrid seeds are a cross between two varieties of the same species with the plants displaying characteristics from each. Hybridisation can be done by hand or may take place naturally in your garden when pollen is carried by wind or insects. Commercial hybrid seeds, identified by ‘F1’ on their packaging, have been bred for desirable traits like strong vigour, increased yields or disease resistance, as well as commercial (but not necessarily gardener) advantages like uniformity, shipping and shelf life. Hybrids are genetically unstable so seed saved from these plants will not usually produce plants that look and taste like the parent. Gardeners and farmers wanting consistent results must therefore purchase new hybrid seeds every year. Hybrid varieties can become open-pollinated varieties through careful selection and breeding over many years.
Open-pollinated seeds are genetically stable so seed saved will produce ‘true to type’ future generations that look and taste like the parent as long as pollination is controlled to prevent accidental hybridisation. Greater genetic diversity of open-pollinated seeds allows them to adapt more readily to changing conditions. Open-pollinated plants are therefore the best choice for most seed savers. Both self- and cross-pollinating plants can have open-pollinated seeds (see page 3).
Genetically modified seeds have genes from another plant or animal species inserted by scientists, and are not usually available to home gardeners.
Heirloom seeds are old, locally valuable open-pollinated plant varieties that have been passed down between generations of gardeners and farmers.
Organic seeds are certified to have been grown in accordance with standards that protect soil health, and prohibit the use of synthetic chemicals, fertilisers, pesticides or herbicides.
Pollination
Pollination occurs when pollen from the male parts of a flower (the stamens) is deposited on the female part (the pistil) of a flower. A single flower can have both male and female parts, but some species have separate male and female flowers on the same plant (eg. pumpkin) and some species have separate male and female plants (eg. asparagus, spinach) so you’ll need at least one of each sex to set seed.
The pollination spectrum
Plants vary in their pollination preferences:
- Self-pollinating plants require pollen to be moved from the male to the female parts of the flower on the same plant. In some flowers the male and female parts are so close that only the slightest movement is needed to transfer the pollen and this might happen before the flower even opens! Cross-pollination is still possible, especially in gardens under organic management with many insects. These ‘inbreeding’ plants can maintain their genepool with a very small number of individuals.
- While some plants sit at each end of the spectrum, many display a preference only and some can be either self- or cross-pollinated.
- Cross-pollinating plants require wind or insects to transfer pollen between plants. These ‘outbreeding’ species must cross with plants of the same species to maintain their genetic diversity and vigour over time. Seeds saved from a small number of plants will eventually become weak or lose characteristics. These plants are more susceptible to accidental hybridization if pollination is not controlled.
How many plants should I save seed from?
To maintain genetic diversity and vigour over time, each species has a recommended number of plants from which to gather seed. Commercial growers are advised to save from a minimum of 10 plants from inbreeding species and as many as 200 plants from outbreeding species! Of course, most home gardeners won’t be able to follow these recommendations. Don’t be deterred! Your seed will likely be ok, but do keep an eye on strongly outbreeding plants (eg. brassicas and corn). If vigour declines, you’ll need to introduce seed of the same variety from elsewhere – a great opportunity to get to know your gardening neighbours or support local heirloom seed companies.
How do I maintain seed purity?
Controlling pollination is optional, especially for strongly inbreeding species like tomatoes and common beans. You may not mind if your Jap and Butternut pumpkins cross to create Jutternuts next year! In fact, many treasured open-pollinated heirlooms originated as accidental hybrids that were allowed to grow and adapt to changing conditions. But if you want to guarantee that the next generation of plants will look and taste like their parents, you can control pollination to maintain seed purity.
All plants of the same species can cross pollinate (eg. the species Lactuca sativa includes all types of lettuce), so this means only allowing plants of the same variety (eg. ‘Red Oakleaf’ lettuce) to flower and cross-pollinate. Remember that pollen from wild weedy relatives or a neighbour’s garden can be carried by wind or insects! In the home garden you can tape, bag or cage flowers to ensure purity, pollinating by hand with a paintbrush where necessary to ensure adequate cross-pollination.
Try to save seeds from as many plants as you can, but don’t be discouraged if you can’t follow the guidelines. Home gardeners rarely have the ‘right’ numbers of plants or control pollination, and results are usually still excellent. It is, however, important to keep these recommendations in mind if you are stewarding a rare variety.

Selecting plants for seed
Keep the best and eat the rest! Breed your own plant superstars using the power of selection at every stage.
If you’re a seed saver, then you are also a plant breeder. The decisions you make about which plants to save seed from are influencing the next generation – for better or for worse – so don’t be tempted to gather seed from weak or diseased plants. You might decide to focus on plants that are early ripening or drought resistant. Or perhaps you’ll select for higher yields or a special flavour. Whatever your priorities, only save seed from your best plants to make sure you are selecting for better results over time. A word of warning – mark plants or fruit for seed saving with tape or ribbons so they are not accidentally harvested for the kitchen!
It’s very important that seed is fully mature before harvest so that it has gained maximum strength from the parent plant. Sometimes this is well beyond the stage that we normally harvest vegetables for the kitchen, so let those tomatoes soften, let your silverbeet flowers reach for the sky and yes, you’ll have to let those zucchinis explode into giant beige marrows. Yellowing stems are a clear sign that the parent plant is dying and seeds have definitely reached maturity. In many species you can monitor seed development by gently squeezing pods or seed heads between your finger and thumb, and with trial and error you’ll learn how early you can harvest them if pests and weather (or your impatience to clear a garden bed) are an issue. Some plants ripen seed progressively, so you’ll need to make a call when say two-thirds are ready, or make several harvests.
Seed cleaning techniques
The other bits of plant that are gathered along with seeds – the stems, leaves and pods – are known as ‘chaff’. It’s not always necessary to remove chaff, but since it can harbour pests and diseases and takes up space in your seed box, cleaning seeds before storage is usually a good idea. There are two basic methods:
Sieving is as simple as it sounds. Experiment with your kitchen sieve and colander or mesh like insect screens. Look for other gauges in op-shops to deal with seeds of different sizes.
Winnowing uses breath or a gentle breeze to separate chaff from seed. It works for seed that is heavier than its chaff. Shake the bowl to bring chaff to the surface, pick out large pieces by hand, then tilt slightly away from you and blow in a U shape around the seed to push the chaff up and over the edge of the bowl. Don’t worry if you lose a little seed too – this is the lightest and therefore weakest. Alternatively, you can pour the seed slowly from one bowl to another, with a gentle breeze (or a small fan) carrying away the chaff.

Wet cleaning is used for seeds encased in moist flesh (eg. pumpkin). Scoop seeds into a bowl of water, rub between your fingers and pick out any large chunks of flesh. Pour into a sieve, rub the seeds gently against the sieve to clean off pulp and rinse under running water. Repeat if necessary. Spread them out on the sieve and leave to dry in a shaded place with good airflow, stirring daily to break up clumps and encourage fast and even drying.
Some seeds are surrounded by a gel (eg. tomato and cucumber) that can be removed easily using fermentation. This treatment may also destroy some seed-borne diseases. Scoop the seeds into a small container with a little water to cover if needed, and leave them for 2-3 days until bubbles or surface mould appear, then proceed with basic wet cleaning.
Dry cleaning is used for all other plants. Seeds can be left to dry on the plant, but if rain or pests are an issue, as long as the seeds are fully mature the pods or the seed head can be cut and either hung or spread in baskets in a warm, shaded, airy space. When the pods or seed heads are dry enough to shatter, thresh them by stripping or crushing into a bowl and rubbing between your fingers to loosen seed from chaff. They can then be sieved or winnowed.
Sieving is as simple as it sounds. Experiment with your kitchen sieve and colander or mesh like insect screens. Look for other gauges in op-shops to deal with seeds of different sizes.
Winnowing uses breath or a gentle breeze to separate chaff from seed. It works for seed that is heavier than its chaff. Shake the bowl to bring chaff to the surface, pick out large pieces by hand, then tilt slightly away from you and blow in a U shape around the seed to push the chaff up and over the edge of the bowl. Don’t worry if you lose a little seed too – this is the lightest and therefore weakest. Alternatively, you can pour the seed slowly from one bowl to another, with a gentle breeze (or a small fan) carrying away the chaff.

Seeds must be properly dried before storage or they’ll be destroyed by mould or premature sprouting (or both!). They should never be heated above 35C though, so don’t put them in direct sun or near a heat source. In Melbourne’s dry climate, a few weeks indoors at room temperature is usually sufficient to complete drying. Shallow baskets are ideal for air circulation, and occasional stirring will help them dry evenly. In humid weather, fans or a warmer microclimate may be helpful for large or wet-cleaned seeds. Dry seeds that are ready for storage will not be dented by your fingernail.
Seed saving by plant family
Rating: EASY
Fabaceae (bean family aka legumes) Eg. beans, broad beans, peas, snow peas
Common beans and peas are self-pollinating and inbreeding. Other bean species are also insect pollinated with some outbreeding. Flowers can be bagged to ensure purity, but pollination control is generally not required for home gardeners. Pods should be opened once harvested to encourage drying or seeds may prematurely sprout or become mouldy. Beans and peas shelled by hand usually require no further cleaning. When very dry, freeze in a tightly sealed container for 3 days to destroy bean weevil eggs, ensuring the container returns to room temperature before opening to avoid moisture condensing on seeds.
Seed viability: beans and peas 3-4 years, broad beans 6 years
Solanaceae (aka solanums) Eg. tomatoes, capsicums, chillis, eggplant, tomatillo, cape gooseberry
Most tomatoes are self-pollinating and inbreeding. Flowers can be bagged to ensure purity, but pollination control is generally not required for home gardeners. Tomato seed is ready to harvest when a fruit starts to soften. Tomato pulp is usually fermented before wet cleaning (see page X). A simpler method for home gardeners is to spread pulp onto paper towel and leave to dry. At planting time there is no need to remove the paper as it will biodegrade, so just tear off the required seeds and plant. Capsicum and chilli are both self- and insect pollinated. Eggplants are insect pollinated and partly outbreeding. Seed maturity is usually indicated by colour change (eg. green to red chillis) and wrinkles on the fruit. Eggplant, capsicum and chilli seeds can usually be scraped out and dried with no further cleaning required. Potatoes are in the Solanaceae family but are propagated vegetatively.
Seed viability: capsicum 3 years, tomatoes 3-10 years depending on variety, eggplant 7 years
Aizoaceae Eg. warrigal greens
Warrigal greens seed forms along the vine, with seed ripening progressively from green to dark brown. Seeds easily detach from the vine and are hard to find on the ground when fully mature, so can be picked green when they have reached full size and dried.
Seed viability: warrigal greens 5 years
Rating: Moderate
Amaranthaceae Eg. silverbeet, chard, beetroot, spinach, amaranth, quinoa
This family is insect pollinated and outbreeding. Dill and coriander are annuals that will grow and set seed in the same year. Many plants in this family including carrot, parsnip, parsley and celery are biennial, so plants must be overwintered before they will flower and set seed. Carrots and their wild weedy relative Queen Anne’s Lace are both Daucus carota species, and may hybridise if pollination is not controlled. Use dry cleaning methods.
Seed viability: carrots and parsley 3 years, dill 5 years, celery 8 years
This family is wind pollinated and outbreeding. Some plants in this family including beetroot, silverbeet and chard are biennial, so plants must be overwintered before they will flower and set seed. Beetroot, silverbeet and chard are all part of the Beta vulgaris species and may hybridise if pollination is not controlled. Use dry cleaning methods.
Seed viability: beetroot, silverbeet and chard 6 years, spinach 5 years
Apiaceae (aka umbells) Eg. carrot, parsnip, parsley, fennel, dill, coriander, celery
This family is insect pollinated and outbreeding. Dill and coriander are annuals that will grow and set seed in the same year. Many plants in this family including carrot, parsnip, parsley and celery are biennial, so plants must be overwintered before they will flower and set seed. Carrots and their wild weedy relative Queen Anne’s Lace are both Daucus carota species, and may hybridise if pollination is not controlled. Use dry cleaning methods.
Seed viability: carrots and parsley 3 years, dill 5 years, celery 8 years
Asteraceae (aka daisies) Eg. lettuce, chicory, endive, sunflower, calendula, marigold, murnong/yam daisy
This family is mostly self-pollinated and pollination control is usually not required for home gardeners. Use dry cleaning methods. Jerusalem and globe artichokes are in the Asteraceae family but are propagated vegetatively.
Seed viability: lettuce 3 years, endive and chicory 8 years, sunflower 7 years
Amaryllidaceae (aka alliums) Eg. onion, spring onions, leek, chives
This family is insect pollinated and partly outbreeding. Onions and leeks are biennial, so plants must be overwintered before they will flower and set seed. Use dry cleaning methods. Garlic and perennial onion varieties are in the Amaryllidaceae family but are propagated vegetatively.
Seed viability: leek 3 years, onion 2 years
Cucurbitaceae (aka cucurbits) Eg. pumpkin, cucumber, zucchini, squash, gourd, cantaloupe, watermelon
This family are mostly annuals that are insect pollinated and partly outbreeding, but their genetics are not severely affected by small populations. Cucurbits have separate male and female flowers on each vine. Male flowers have a long, narrow stem, while female flowers have an immature fruit at the base of each flower. There are four species of pumpkin – Cucurbita moschata, Cucurbita maxima, Cucurbita mixta and Cucurbita pepo (which includes zucchini) – so check the scientific name of your variety to see if it may hybridise with other pumpkins or zucchini growing nearby. Seed purity can be ensured using hand pollination. Identify male and female flowers the night before they open and tape shut to prevent insect entry. In the morning, cut male flowers, remove petals and brush inside female flowers. Tape female flowers shut until they wither, and mark with a ribbon. Note that many vegetables in this family are picked immature for the kitchen (eg. cucumber, zucchini) and must be fully mature before harvest for seed, usually indicated by a colour change. Seed will continue to increase in strength and size for 20 days after mature fruit is picked. Use wet cleaning method. Cucumber seeds may be fermented for 2-3 days before cleaning. Chokos are also in the Cucurbitaceae family but their seed is unable to be removed from the fruit. When the fruit begins to shoot, it is planted half-submerged, with the shoots just above ground level.
Seed viability: pumpkin and zucchini 6 years, cucumber 10 years, watermelon 6 years, melon 5 years
Rating: Advanced
Poaceae (aka grasses) Eg. corn, maize, native edible grasses
This family is wind pollinated and strongly outbreeding, requiring a large number of individuals flowering together to maintain genetic diversity and vigour. Corn should be planted in large blocks (not narrow rows) to ensure good seed set. Kernels can be removed from the cobs when very dry.
Seed viability: sweet corn 3 years
Brassicaceae (aka brassicas) Eg. broccoli, kale, cabbage, cauliflower, Brussels sprouts, radish, mustard, kohlrabi, turnip, bok choi, pak choi, tatsoi, rocket
This family is insect pollinated and strongly outbreeding, requiring a large number of individuals flowering together to maintain genetic diversity and vigour. The species Brassica oleracea includes broccoli, cabbage, most kales, Brussels sprouts, kohlrabi, collards, cauliflower and many wild weedy relatives, so all these plants can hybridise if pollination is not controlled! Use dry cleaning methods.
Seed viability: cabbage, kale and collards 4 years, bok choi, pak choi, tatsoi, mustard, turnip, radish, broccoli and cauliflower 5 years
Storing and sharing your seeds
Dry seeds can be packaged in glass jars, paper bags and envelopes or reused plastic bags. Label with the variety, location and year collected, and store them in a tightly sealed box that is rodent, weevil and moth proof.
Most vegetable seeds will remain viable for 3-5 years if they are kept cool, dark and dry. Don’t be tempted to store them in your greenhouse, garage or garden shed where fluctuating temperature and humidity will reduce their lifespan. Seeds make a beautiful display, but the best place for long term storage is somewhere considerably less glamourous – under your bed perhaps, or in a cupboard on the south side of your house?
If you’ve followed this guide, you’ll probably have more seed than you could ever dream of planting, so do make a plan for your surplus. Will you gift it to family, friends and neighbours? Will you share it through a seed library, or join (or even create!) a local seed savers network?
Whatever your choice, enjoy the small miracle of growing, saving and sharing your seeds and thanks for doing your bit to preserve our precious seed heritage.
References
Seed Savers Handbook – Michel and Jude Fanton
Seed to Seed – Suzanne Ashworth
Breed Your Own Vegetable Varieties – Carol Deppe