With the availability of commercially grown seeds, there was less focus on seed saving. Farmers and gardeners would simply purchase new seeds every year. However, due to the fear of losing available seed options, a movement arose in the late 70s to early 80s to save seeds.
Heirloom and traditional crop varieties are becoming less prevalent, so today people are recognizing the importance of conserving them. To save seeds and maintain purity, both home gardeners and seed bank operators need to follow some basic steps. Here are some basics to get you started.
What Seeds to Save
Some are challenging to collect, while others are more delicate and require special handling. Many plants produce a large number of seeds, which can be harvested and used for various purposes. Not all seeds are of equal value or easy to collect, so it is important to choose the right ones. Some seeds require special care when handling them.
National Gardening Association F1 and hybrid varieties of plants are created when two inbred parents of different but related plant species are bred. These offspring often have desirable traits such as higher yield or size, but if you try to grow a plant from their seeds, the results will be unpredictable and the plant will not be true-to-type.
F1 hybrids must be bred every time by crossing the same parents in order to achieve uniformity and hybrids that are vigorous and excel in growth in comparison to their parents.
Seeds from hybrid plants are not reliable for saving and replanting. The plants may be sterile, or the next generation may have widely varying characteristics. These seeds are better for farmers who need produce that is uniform in ripeness and size, which makes harvesting and production easier. However, these seeds usually require high inputs of fertilizers and pesticides.
GM (genetically modified) seeds are created in a laboratory by taking genes from the DNA of one species (such as a herbicide) and artificially inserting them into the genes of an unrelated plant. This is different from traditional genetics methods, such as selective breeding, tissue cultures, and hybridization, which help nature but do not bypass natural laws. There have been many studies documenting the health risks of GM crops, as well as ethical and environmental concerns about GM seeds and plants. From a seed-saving perspective, they are not suitable because they are patented and you would have to pay royalties to reproduce them.
So, if you avoid hybrid and GM seeds, what types of seeds are you left with?
Open-pollinated seeds are seeds that are pollinated naturally by insects, birds, animals, wind, and moisture. They will produce plants that are clones of the parent. Open-pollinated seeds come from stable, non-hybrid varieties of plants resulting from pollination between the same or genetically similar parents. They are also known as ‘true’ or ‘pure-bred seeds’. The parent plants produce matching seeds – similar to identical siblings! All the plant family looks and behaves the same.
To ensure you are not using chemically treated seeds when growing food crops, it is best to find untreated, certified organic, or heirloom seeds. This way, you can be sure the seeds have not been exposed to any chemicals and will produce healthy plants.
Heirloom seeds are non-hybrid plant varieties that have been passed down from one generation of growers to the next. These varieties are often not used in modern agriculture, and may be hard to find in supermarkets. Heirloom varieties are valued for their unique characteristics, including flavor, size, color, aroma, and resistance to pests and diseases.
The text is discussing local varieties of plants, which are those that have been grown in one area over a long period of time. You can sometimes learn about the history of these regional varieties by looking at seed companies that support local seed savers, or by checking with seed saving organizations.
Based on my personal experience, I’ve observed that when I initially plant seeds from another region, the plants aren’t always at their best the first year. They’re adjusting to the new environment! However, after spending a season in my soil and microclimate, they have adapted to maintain a new level of resilience. Sometimes, I’ve noticed the plant grows taller or beans have more flowers and pods, or they are more drought-resistant in the second year. Over time, this natural selection process promotes greater diversity and adaptation to the new conditions with each generation, until the plants are strong and at their best.
Pollination is the process of transferring pollen from the male anthers of a flower to the female stigma. This process is necessary in order for fertilization to take place and for seed production to occur. When the pollen comes into contact with the stigma, it causes a chemical reaction which results in the formation of a pollen tube. This pollen tube then grows down the length of the pistil until it reaches the ovary, where fertilization takes place. The ovule then develops into a seed.
Self-pollination is when the pollen from the male part of the flower is transferred to the female part of the flower on the same plant. This can happen within the same flower, or when pollen from one flower is transferred to another flower on the same plant. Some plants have specific mechanisms in place to ensure self-pollination occurs. For example, in beans, pollen transfer happens within a flower before it even opens.
Most flowers have both male and female reproductive organs (perfect flowers). However, some flowers are imperfect and have either only male or only female organs. These flowers rely on cross-pollination, which happens when pollen is carried from a male flower to a female flower by the wind or by insects. The flowers can be on the same plant (monoecious) or on different plants (dioecious). For example, cucurbits like squash, melons, and gourds have imperfect flowers that are male and female, but they grow on the same plant (monoecious). This means that the pollen has to be moved between the male and female flowers by insects in order for the plant to produce fruit.
Isolating Distances Used for Maintaining Genetic Purity
To maintain seed purity between cross-pollinating crops, growers can prevent unwanted crossing from occurring by following some guidelines. The “one-quarter mile” rule is the standard isolation distance to prevent pollen from one variety from contaminating another during the growing cycle, but this may be a bit extreme in the southwest’s arid climate. Corn pollen can easily survive in high humidity, but quickly desiccates in low humidity and drying winds. Insects carry pollen considerable distances but must stay near a water source, so in hot, arid conditions, isolation can often be accomplished at distances of less than one-quarter mile.
Annuals, Biennials, and Perennials
It’s vital to know what kind of plant you are saving seed from. They are divided into three types:
Annuals are plants that complete their life cycle or produce seeds and die, in one growing season. For example, lettuce, beans, peas, pumpkins, cucumbers, melons, basil, coriander, broccoli, and annual radishes.
Biennials require two seasons to complete their life cycle and then produce seeds and die. These include cabbages, onions, leeks, beetroot, parsnips, celery, parsley, and carrots.
Perennials live for a minimum of three years, but some can live for decades. They usually can produce seeds and not die. Edible perennials include many herbs, such as oregano, thyme, and rosemary, as well as berries, rhubarb, artichoke, asparagus, tomatoes, eggplant, and chillis. Seed saving is not as imperative for these plants as it is for annuals.
What to Select
The way in which plants are harvested depends to some extent on whether the intention is to keep the same variety or to choose particular qualities. If the aim is to keep the same variety, it is best to save seeds from as many separate plants as possible, even if there is only one seed per plant. If the seed takes some time to mature, it is advisable to save seeds from several harvests, so that the seeds from plants which mature early or late are both represented in the sample. This increases the chances that the genetic diversity will be preserved in the seed sample. On the other hand, if the objective is to select for particular qualities, it is only necessary to save seeds from those plants which have the desired attribute.
Timing of Harvest
The time to harvest crops that bear “dry” fruit, like chili peppers, black-eyed peas, squash, okra, amaranth, sunflowers, corn, peas, garbanzos, cotton, most greens and herbs, sorghum, tobacco, and wheat, is when the fruit or seeds are dry. You’ll know they’re ready when the seeds rattle in their pods or have started to fall from the plant. Crops can be left in the field until they’re completely dry or harvested and placed in a protected area to finish drying.
The fruit is ripe when the bottom side is whitish and the tendrils on the fruit-bearing stem and two adjacent stems are dry. The fruit is typically split and the seeds are scooped out of the fruit, washed, and allowed to dry on cloth towels or pillowcases out of the light and heat.
The following are typically mature, and therefore ready to be harvested, when dry:
Amaranth – cut seed head when the majority of flowers feel stiff to the touch, continue drying in a paper bag, pillowcase or on a metal tray to collect seeds that drop.
Beans/Black-Eyed Peas/Peas/Favas/Lentils/Tepary Beans – pods should be dry and can be picked by hand or by cutting the plant at ground level, letting dry on a tarp out of the rain and threshed.
Chiles – allow chiles to dry on the plant, and hand harvest.
Corn – if temperatures are high, harvest sweet corn when kernels harden just after the milk stage (milk stage is the ideal fresh-eating stage when a fingernail pressed into a kernel produces a white, milky liquid); sweet corn left too long on the plant in high temperatures may begin to ferment in the husk; for other corns, the cobs may dry completely on the plant, unless frost is likely or birds become a problem; remove entire cobs from the plant.
Gourds – allow to dry on the vine until just before the first frost, then continue drying out of the rain; can take several months; gourds are dry when seeds rattle.
Okra – let dry on plant but harvest before fruit opens allowing the seed to drop.
Sunflowers – let dry on plant as long as possible, protect from birds by covering seed heads with netting or pillowcases; cut heads and let dry in a cool, dry place or in paper bags.
Melons, watermelons, and squash are typically mature and ready to be harvested when the tendrils are dry on the fruit-bearing stem and the two adjacent stems. Some crops require a period of after-ripening in order for the seeds to fully mature. After harvesting, allow squash to after-ripen for 21 days before removing seeds.
Choosing Seed for Saving
As with every step until now, it’s important to keep an eye on quality. Below are some basic guidelines to consider when saving seeds:
Choose healthy, undamaged seed to save
Do NOT keep seeds from diseased plants (some viruses are transmitted through seeds)
Save seed from as many plants as possible
Be sure seeds are clean of unwanted sticks, chaff, seed pods, etc. This will reduce the bulk that is stored as well as the threat of some possible pests and diseases.
Keep enough seeds for next year’s planting needs.
Early Seed Formation
Choose a plant to save seed from and take care of it during its reproduction phase when it needs extra water, nutrients, and protection.
To have viable seeds, it is important to have healthy plants that produce them. When the plants are first beginning to flower, it is a crucial time for the final seed viability. The plants should be strong, healthy, and minimally stressed during early seed formation and development. Give the seed-producing plants plenty of water, light, and fertilizer early on in their lives, so they are healthy when flowering starts.
When some plants mature and produce flowers and seeds, they may become top-heavy and fall over. To prevent this, staking may be necessary.
Watering During Seed Formation
It is essential that there is enough moisture at the time of flowering so that the pollen can develop and the flowers can set. If there is not enough water during the early stages of seed development, then the seed yield will be lower and the health and vitality of the mature seeds could be affected.
It is preferable to have dry conditions during the latter stages of seed maturation. This is when seeds have formed and are drying in preparation for dormancy. Dry conditions are most favorable to the final vigor, viability, and storage life of your finished seeds.
When mature seeds get wet from watering or rain, it slows down their natural process of preparing for dormancy, which extends the time during which their stored food reserves must be used for respiration. This lowers the seeds’ final dry weight and shortens their storage life.
If you repeatedly wet and dry mature seeds that are still on the plant, it will delay dormancy excessively and can also damage the seeds. This is because the seed tissues alternate between swelling and shrinking. If you leave the seeds on the plant during rainy periods, they may mold or mildew in their pods or husks. So it’s best to harvest your seeds and bring them inside for final drying as soon as they are fully mature and dry— especially if rains are coming.