Seed Saving

Seed Saving



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Why save seed
To not save seeds is to be reliant on seed companies and to miss an opportunity to get lots of free seed. What’s more saved seeds are adapting to the local growing conditions, which will make crops more productive and resistant to pests and diseases.

By some simple selection for desirable traits we can help this process along, creating our own locally adapted vegetable varieties. Seed saving by gardeners is also the only way most rare and heritage varieties can be kept from extinction.

How to save seed
Select seed from plants with characteristics you like and that grow well and quickly in your conditions. But don’t collect from only one plant, you will be breeding out diversity and the ability of the crop to adapt.

Not all seed collected will necessarily produce offspring that are “true to type”, that is share the good characteristics of the parent plant.

Seed saved from F1 hybrid varieties will not produce plants like the parent plant. Choose only non-hybrid seeds, known as open pollinated.


Plants from the same species can cross with each other producing mixes of the parent plant. Although this can be a good thing if you are trying to breed a new variety, often this must be avoided it can destroy the useful original traits in distinct crops.

In order to avoid crossing it is necessary to know a little about how plants reproduce. Unlike animals most plants have organs of both sexes. These are located sometimes in the same and sometimes in different flowers. The male portion of the flower produces pollen. These tiny grains have to pass onto the female part of the flower that is receptive to pollen, known as the stigma, in order for a fertile seeds to be produced. This process is called pollination.

In order to avoid unwanted crossing and to produce viable seed, pollen from a variety must reach and pollinate the female flowers of that plant, while pollen from other varieties must be prevented from reaching the stigma.

This can be done in one of four ways:

  • Plant only one type of any group of plants that can cross.
  • Grow plants that can cross at a staggered time interval, so that plants will not be in flower at the same time.
  • Carry out pollination by hand and physically prevent other pollen reaching the flower by such methods as bagging and taping up of flowers.
  • Isolation. Keeping plants far enough away from each other to avoid cross-pollination, or using methods such as caging.

Which methods are suitable depends on the type of pollination. Plants are pollinated in three differing ways, by wind, insects or by what is known as self-pollination.

The self-pollinated crops are most tomatoes, beans, lettuces, peppers and aubegines. These are by far the easiest to save true to type seed from, because the pollen is transferred directly to the stigma within the flower. With beans all that is generally required is to separate crops by a few feet to avoid pollen being transferred to an adjacent variety. Insects may occasionally pollinate some of the self-pollinated crops such as peppers.

Insects pollinate most crops, an isolation distance of a few hundred feet is generally sufficient to avoid almost all crossing between compatible plants flowering at the same time. It is possible to grow more than one insect-pollinated crop much closer together and avoid cross pollination using physical barriers and distractions to help keep insects from visiting both varieties.

Aleta Anderson from a Washington based seed saving group, explains ‘Barriers, hedgerows and lots or nectar-bearing plants are important parts of maintaining isolation. If there’s plenty of nectar to choose from insects are more likely to stay in the place they are in, enjoying lunch from the bounty they have… We use these techniques regularly and have found them to be successful’.

Wind pollinated crops are corn (maize), spinach, amaranths, beets and Swiss chard, these are the most difficult to prevent from crossing. There must be no other varieties within at the very least a 1/4 of a mile, depending on wind direction, shedding pollen at the same time. If there is, some of the harvested seed will result from a cross between these two varieties. The closer the varieties are located, the higher the amount of crossed seeds.

What can form crosses?
What crops will cross with each other is not always obvious.

Squashes, pumpkins and marrow are from 4 different species of cucurbit, except where noted types of each species will only cross with each other.

All of species Cucurbita pepo = Courgette/ Zucchini, Marrow, Squash varieties-inc. Spaghetti, Acorn, Scallops, Crooknecks, Cocozelles. Mature plants have prickly leaves and stems; seeds are small and white.

All of species Cucurbita maxima = Common Pumpkin and Winter Squash varieties- inc. Buttercup, Hubbard, Banana, Turk’s Turban. Most cold hardy species, seeds are thick, yellow and have a plastic-like coating.

All of species Cucurbita moschata = Squash varieties inc. Butternut, all Cheeses, Distinguishable by white patches on leaves.

Cucurbita mixta = Squash varieties inc. Green striped cushaw. Plants similar to in appearance to C. pepo, and may sometimes form crosses with that species. Seeds are grey.

All of species Brassica oleracea = Cabbage, Broccoli, Cauliflower, Kale, Brussels sprouts, Kohl-Rabi

All of species Brassica rapa = Turnip, Chinese and Asian cabbages inc. Pak-Choi, Mizuna, Mustard-spinach

Members of the brassica families Brassica rapa, B. napus (rape, swede/ ratabaga) and B. junecea (Indian and oriental mustards, leaf mustard) have been known to make fertile crosses with each other

All of species Beta vulgaris = Beetroot, Swiss chard, Sugar beet, Fodder beet/ Mangel

Both of species Cynara cardunculus = Cardoon and Globe Artichoke

Both of species Lactuca sativa = Lettuce and Celtuce (Stem lettuce, Asparagus lettuce)

Endive and escarole, Cichorium endiva, can pollinate Chicory, Cichorium intybus, however endive itself is self-pollinating and cannot be can pollinated by chicory.

Wild relatives
Many crops can cross with their wild relatives. Brassica nigra, Brassica rapa, Cardaria draba, Raphanus raphanistrum, and Sinapis arvensis are common agricultural weeds all through the northern hemishere and can create problems for seed savers by hybridizing with brassica crops. The other two common weeds in cultivated ground our part of the world that can form crosses with their cultivated cousins are the wild lettuce Lactuca serriola, and the wild carrot, Daucus carota, known as Queen Anne’s lace.

Collecting Seeds
Many common crops are biennial and will produce seed only in their second year, these are the brassicas (except for radish and mustards that are annuals, and perennial horseradish), onions and leeks, beets and chard, parsnip, carrot, celery and celeriac, parsley, salsify and chervil.
Common onions, Allium cepa are generally dug up at the end of the season, good sized bulbs are chosen and then replanted to grow for seed

All seed collecting is best done during dry weather.

Crops that produce their seed in pods:
Peas, beans and brassica family (includes cabbage, broccoli, cauliflower, turnip, radish, mustard, kale and kohl-rabi).
Easy to collect, just leave pods on the plant until they are dry. Harvest before the seed is dispersed.

Crops that produce seed inside fruits
Squash family (pumpkin, cucumber, courgette, marrow), tomatoes, peppers, aubegine and physalis.
Easy to collect, leave fruits to mature as long as possible to ensure fully developed seed. Leave tomatoes to go over ripe and leave summer squash and pumpkins on the vine until after frost. Separate the seed from the fruit pulp and dry at room temperature.

Seeds borne on top of a flower stalk
Grains, onion family, carrot, parsnip, beets, spinach, lettuce, celery, fennel, chicory, salsify and most herbs including parsley, basil, coriander and dill.
Seed usually small and produced in multitude, collect after they are dry but before dispersal. Give a light tap to the dry flower stalks, if seeds rattle or are dislodged, they are ready for harvest. Many plants produce seeds over a period of time, visit regularly and shake stalks over a container.

Small seeds are winnowed to remove the unwanted plant debris, or chaff. This can be done by pouring into a container in a breeze that carries off the chaff and dust, or through an appropriately sized sreeen or sieve.

Storing Seeds
Thorough cleaning before storage is good protection against pests and diseases. Drying is essential to prevent stored seeds rotting or going moldy. Spread them out in a warm, dry, well ventilated place, stirring them occasionally

Paper and cloth bags are adequate storage materials in a dry place. Airtight glass jars can help protect against humidity and rodents. Peas and beans and other large seeds with moist fleshy insides store best in breathable containers. A refrigerator is an excellent place to store seeds.

Seeds are alive; they metabolize even in their dormant state and gradually use up their carbohydrate reserves. While some vegetable seed can remain viable in storage for as long as 15 years or more, and grains may remain viable much longer under stable environmental conditions, every year in storage will decrease the amount of seed that will germinate. Seed is best sown the following year after being collected.

Seed Exchanges
When seed saving it is easy to collect far more seeds than one grower’s needs. Seed exchanging is a very old custom. In recent times many grassroots seed exchanges have developed. These groups are performing a vital role preserving rare varieties and championing biodiversity. If there isn’t a seed exchange in your area why not set one up and share the wonders of diversity with others.