Digging in the Dirt > Gardening Information > Completing the Cycle: Saving Seeds

Completing the Cycle: Saving Seeds
Edited by Jordan Rainwater and Scott Vlaun

Even though we are a company that grows and sells seeds as our business, we encourage everyone to learn the art of seed saving. Of the many facets involved with growing, nurturing and gathering plants, the raising and collecting of seeds for future generations is a reverent act.

Collecting the seed of any plant, whether a vegetable, flower, herb, tree or shrub, completes a cycle begun when the initial seed was placed in the earth. By growing and collecting seeds, we connect with ancient practices that have played a critical role over generations in the preservation of food, medicine, fiber, fuel and ornamental plants. Furthermore, saving seeds and replanting them in your garden from year to year allows succeeding generations of plants to adapt to your particular location.

While we us a lot of complex equipment to meticulously clean our seeds, the process described here is a simple version of what we do at Seeds of Change. Unlike many other seed companies who buy their seeds on the vast commercial markets-already selected and cleaned-we do this work ourselves on our Research Farm in New Mexico and in conjunction with our network of family farmers. The processes described below should result in sufficient quality for the home growers needs.

  How Plants Make Seeds

Perfect Flowers
To grow and save common garden seeds, you have to understand some basic rules about how plants reproduce, and how we can, by our growing practices, maintain the purity of characteristics we treasure. Plants such as beans, tomatoes, lettuce, amaranth and peas have what are known as perfect flowers, which means they have both male and female parts in a single flower. This enables them to self-pollinate without dependence upon bees, insects or the wind to carry their pollen.

	Dancing bean seeds out of their pods. A quick two-step...
	After the dance: the beauty of Jacob's Cattle bean emerges.
	Winnowing Jacob's Cattle beans.

The fact that these common food plants usually do not cross-pollinate permits the gardener to grow literally hundreds of varieties in close proximity to one another, and to establish a diverse seed collection to share with friends and others who are interested in the conservation of varietal diversity. You can control rare incidents of cross-pollination with these varieties by removing any plants that are "off" in appearance in the following season's growout.

Imperfect Flowers
Plants that have separate male and female flowers on each plant are said to have imperfect flowers. These flowers need pollen-carriers like the wind, honeybees, other insects or humans in order to be pollinated. Plants in the same Genus species have to be kept a safe distance from each other or cross-pollination will produce new varieties that may or may not be desired by the grower. Usually this is around 500 feet but varies by species. Seed to Seed by Suzanne Ashworth is a good reference to determine proper isolation distances for seed saving purposes and a great source of information on seed saving in general.

Plants with imperfect flowers make up most of what we grow to eat in our garden: parsley, celery, chard, spinach, cabbage, cauliflower, broccoli, kale, mustard greens, Chinese cabbage, radishes, carrots, beets, onion, leeks, basil, chiles, turnips, and eggplants. All will cross-pollinate readily within their own Genus species, so it's better to grow one variety of each type to maintain the purity of characteristics you value in these open-pollinated varieties (basil that bolts late, for example, or early ripening in chiles in short growing season areas).

Preventing Cross-Pollination
If you want to grow more than one variety of these kinds of plants, institute careful isolation practices, and pay close attention to the growth cycle.

Crops such as corn can be planted at different times to offset flowering sequences and give pure strain results. One method is to plant a short-season variety as early as possible and plant a main-season variety two or three weeks later. The early crop will tassel and drop pollen before the next crop begins to tassel or show silk from new ears forming. Doing this almost always works, but to minimize risk in case there are lingering tassels carrying pollen from the earlier variety, plant plots in rectangles facing head-to-head instead of side-by-side in the garden. To maximize the purity of the seeds, collect off the opposite ends of the garden plots where the chance of cross-pollination is the slimmest.

Because crosses among the varieties found within each of the commonly grown squash groups can occur, it is best not to plant more than one variety of each species. That means only one of the Cucurbita pepo (pumpkins, summer squash, spaghetti, delicata), one of the C. maxima (winter squash, hubbard, hokkaido, kubocha, buttercup, sweet keeper, red kuri), one of the C. moschata (tahitian, butternut, cheese types), and one of the C. mixta (includes all cushaws, and many green-and-white striped varieties that yield drier fruit but excellent eating quality seed. The varieties of C. mixta that produce the best eating seed are in a group known as C.argyrosperma). Following this method, you can safely plant one variety from each group and have pure lines from each.

Cucumbers and melons are also better off being grown without other varieties of their kind close together. So choose one cantaloupe or honeydew, one watermelon and one cucumber. The same applies to gourds and luffas.

Working with Biennials
Many of the above cultivars are biennials, meaning they produce seed in their second season. Parsley, celery, kales, cauliflower and broccoli can be over-wintered in the ground under some mulch or other protection from severe cold. Carrots, onions and beets can be dug up and stored for replanting early the following spring so they can flower later that season. One advantage to digging up the vegetable, aside from avoiding cold and weather damage, is that one can select for desired characteristics in the root shape, flavor, size and texture, and check for insect infestations, rot or fungus as well.

Harvesting Seed
Apart from learning the basic guidelines of how plants produce seed, we need to become familiar with the signs of maturity that indicate when seed is ready to be harvested. The ripe flowers of herbs, ornamentals and many vegetables have exposed seeds emerging from capsules, or bracts, or from behind withering petals. The flowers will be faded in color and appear dried out, and, in the case of lettuces and daisies, a puff-like top such as is commonly seen on dandelions will appear.

When these signs become evident, guard against mature seeds dropping to the ground or suffering from exposure to the elements. Pick or clip the seed heads into a bucket or sack and lay them out to finish drying in a warm place protected from wind and rain. We use an empty greenhouse for this purpose and it works very well for thorough drying and completion of the curing process. Shade cloth can be used to protect curing seeds outdoors from ultraviolet rays if the sun is too strong.

Seeds of brassicas such as mustards, bok choy, kale, cabbage, broccoli, cauliflower and radish develop in pods that are exposed and brown when ripe. The key is to harvest them just before the pods begin "shattering" and releasing the seeds. It is best to pick a full flowering stalk even if a portion of it is slightly green instead of waiting for it to brown all the way down and risk the first-to-ripen seeds dropping to the ground. Seeds of chenopods such as spinach, chard, beets, lambsquarters and quinoa produce exposed seed that protrude from a flowering cluster. Collecting chenopod seeds is recommended when 90 percent of the seeds are mature.

Harvest corn seed from ears picked when the plant is fully mature and cured until the seed is dry enough to break off the cobs. Should the threat of frost result in the corn not being fully mature when picked, curing can be done with ears laid out in a warm location until thoroughly dried.

Dry Seed Cleaning

	Seed and chaff awaiting separation...
	Winnowing the seed.
	Using a screen to clean lettuce seed.

Cleaning seed is one of the most satisfying activities involved in taking seed to seed. It is the one that completes the life cycle and brings us back to the beginning again. Seeds are cleaned either through a wet or dry process.

Seeds that are cleaned with the dry method include: flowers, herbs, mints, onion, umbels, berries, corn, grains and beans. Seeds from these plants can easily be cleaned to a functional quality for storage and planting with the use of some basic equipment.

A framed screen with a quarter inch mesh is a versatile threshing tool for the initial stages of cleaning several kinds of seeds. Push the bulk material through the screen into a wheelbarrow so that it can be easily maneuvered when sifted. Finer sifting can be done with screens of different sizes. Old bread pans and bowls of different sizes are useful to hand-work small batches so that heavier chaff material can be picked out. For small lots of seed, most of the chaff can be eliminated if you move the seed around in the pan while blowing gently and steadily. Pouring seed between two bowls on a breezy day can also separate seed from chaff. Winnow over a sheet or tarp in case you remove too much viable seed, in which case you can winnow it again.

For larger quantities, a common box fan with 3-speed adjustment is a very accurate winnowing tool for most seeds, except the very lightest. By starting low, with the fan set up on a box 6 to 12 inches above a sheet, you can find the right velocity to achieve extremely accurate separations of seed from chaff. The fanning will produce a pile where the darker, heaviest and best seed is usually closest to the fan, and lighter seed and chaff is furthest from the fan. The seeds that are lighter in color are of lesser quality, but usually will still grow good plants. They are worth passing on to a charitable cause or broadcasting into a wild garden area or naturally moist ditch bank.

Wet Seed Cleaning
The seeds of melons, squash, cucumbers, tomatoes, eggplants, tomatillos, citrus, passion fruit, cacti and some chiles are all cleaned or separated through a wet process and dried for storage or replanting. Many undergo a fermentation period where seeds sit in their own juice, slightly watered down, at a water temperature of between 60° - 75° for 24 to 96 hours. Fermentation actually eliminates seed-borne viruses, breaks down the gelatinous coating around the seeds, and very functionally enhances separation of fertile and infertile seeds.

In the wet seed cleaning process, fertile seeds sink to the bottom, while pulp and hollow seeds float to the top. With cucurbits such as melons, squash, or cucumbers, scoop out the seed and fruit after cutting the fruit in half and drop them into a bucket to ferment in their own juice to which a little water has been added. Watermelons, squash and luffas are quick to drop fertile seed within two days at 65°-75°. Cantaloupes take another day and cucumbers up to 4 days before pouring off can take place. During the fermentation period, stir once a day or more to promote the breakdown of pulp.

Ripe tomatoes are mashed through a quarter inch hardware screen into a bucket to ferment. Like the cucurbits, fermentation will take place in 2 days at a temperature of 65° - 70°. The fertile seeds will sink to the bottom of the bucket and the infertile seeds will float to the top. Pour off the liquid so that the infertile seeds and floating pulp are carried away.

Several additional rinsings may be required to remove any pulp that has sunk to the bottom of the bucket. Finally, pour off into a strainer and lay the seeds out to dry on a nylon window screen in a warm location between 80°-100°. A house fan placed nearby will increase air circulation around the seeds and speed up the drying process. As drying progresses, some caking will take place in which the moist seeds clump together. Just rub the clumps apart gently so drying can continue.

Thick-walled, hard-to-dry chiles or peppers do not need to ferment. A simple soaking for 24 hours will release the seeds and separate the fertile from the infertile ones. Cut the fruit open and remove the seed cluster to enhance the releasing process. Pour off infertile seeds and once again collect the seeds that have sunk into a strainer. Lay them out to dry as you did with the tomato seeds, but be careful not to over-expose the seeds to the hot sun. Chile seeds are less sun tolerant and prefer partial shade.

Storage
To maintain best, long-term viability, keep seeds in a moisture-proof, sealed container at 40°-50° F with low humidity in a dark place.

Final Advice
Some final reminders to help you throughout the seed growing cycle...

Plant Placement in the garden or field is extremely important for controlling water, cross-pollination, lodging (when plants fall over it's called lodging), and your access into the crop (err on the side of too much room). Once you have observed a full cycle or two of a given plant, you'll develop a feeling for its optimum placement in the garden.

Irrigation of seed crops requires close attention to the maturation process. Be careful not to water when seeds are maturing or exposed and open. If irrigation is necessary, do it after picking sequences, not before. This is true with fruiting crops such as melons and tomatoes too.

Weeding and Cultivation is an art in all horticultural grow-outs. When growing for seed, you should be impeccable about keeping your crops clear of weeds to insure your stock is not contaminated by weed seeds and to make it easy to harvest.


We are truly blessed by the hand of natural selection when it comes to working with the earth and growing plants. We hope this information is useful to furthering an interest in growing and collecting seeds, and enables you to share the joy of seed saving.

We highly recommend Susan Ashworth's Seed to Seed for the best, in-depth instructions for saving seeds from most common varieties of garden plants.

This article was edited by Jordan Rainwater Scott Vlaun, but it represents the efforts of many Seeds of Change "seedspeople" over the last 15 years.