Seed Saving: How to Plan Your First Foray

Whether you’re a home gardener or a more seasoned horticulturist, saving seeds is a time-honored tradition vital to the preservation of important varieties of vegetables and herbs. During a time when genetically modified crops and hybrid seeds are all too common, there is a growing appreciation for seed saving of time-tested, open-pollinated cultivars.

The following is an excerpt from The Seed Garden: The Art and Practice of Seed Saving with contributions by Jared Zystro, Micaela Colley and edited by Lee Buttala, Shanyn Siegel. It has been adapted for the web.

Forays into seed saving often begin quite simply, when gardeners opportunistically collect seeds from a self-pollinating cultivar as the seeds present themselves in the vegetable garden. While a gardener needs only a minimal understanding of what a species requires in order to produce true-to-type seeds in this case, such a simple act of seed saving often proves successful and leads a gardener down the path of collecting seeds from other crops. From there, the education of a seed saver evolves as new skills are acquired and an interest in growing a wider range of seed crops develops. As seed savers gain experience, they learn to balance the many factors that comprise the art and practice of seed saving.

The first step in planning a seed garden is determining the scale and scope of a seed-saving endeavor. The best advice is to start small and with familiar crops that one has grown before. To choose varieties from which seeds can be success-fully saved, one must understand the conditions, isolation distances, population sizes, and length of season that different species and varieties require to produce viable seeds.

Mapping out the garden for efficient use of space to produce both vegetables and seeds should also be considered when planning a seed garden. In addition, a gardener needs to determine what the primary goal is in saving seeds: Are seeds being collected simply for sowing in the garden the following season, or for the conservation of a rare variety?  A careful consideration of these factors (bearing in mind how much effort one is willing to invest) is the starting point of planning a seed garden, whether a gardener is a novice or a practiced seed saver.

Choosing Seed Crops

Gardeners tend to want to collect seeds from the crops they grow most, but it is essential to deter-mine first if it is feasible to cultivate seeds from a particular species. Seed savers must examine whether they can grow a species to seed given its spatial and cultural requirements. And, because varieties of the same species can differ dramatically in the time it takes them to reach maturity, seed savers must also ask whether or not seeds can be collected from a specific variety.

It is critical to remember that while seeds produced by a hybrid, or F1, variety are occasionally grown out by breeders and advanced seed savers in an effort to stabilize the traits of the variety, such seeds are highly unlikely to develop into plants that closely resemble the original variety. Open-pollinated varieties, on the other hand, will produce seeds that are true to type and maintain the desired characteristics of their variety pro-vided a seed saver takes care to prevent unwanted cross-pollination between cultivars.

Regional and climatic conditions should also be taken into consideration when selecting seed crops. Knowing what species and varieties grow well as food crops in local conditions is useful in determining what can be grown for seed. For annual crops, it is essential to calculate whether the fruits and seeds will have time to mature before the end of the season.

Most seed packets include information about the number of days to maturity, which is an estimate of how many days a variety needs from germination—or transplanting—before it can be harvested for eating. For annual crops that are normally harvested at botanical maturity, such as tomatoes, winter squash, and grains, the days-to-maturity figure is a relatively accurate predictor of when seeds will be ready for harvest. Annual crops with fruits that are usually harvested when botanically immature, such as eggplants, snap peas, and cucumbers, need additional time—often several weeks or more—beyond the estimated days to maturity before their seeds will mature.

Although watermelons are typically thought of as a southern crop, ‘Blacktail Mountain’ watermelon is an early-maturing variety that was originally developed to mature fruit in northern Idaho, where summer night-time temperatures fall below 50°F (10°C).

Annual crops grown for their leaves, stalks, or roots also require additional time beyond market maturity, but this amount of time varies from species to species and even from variety to variety. In the case of seed crops where information on the days to seed maturity is not easy to find, the best a seed saver can do is experiment to see if the season is long enough to allow seeds to fully mature.

The days-to-maturity figure can also guide seed production of biennials so that they reach an appropriate size for overwintering, which is often slightly smaller than full size, but depends on the manner and climate in which they will be over-wintered. Biennials can only be grown for seed if they are exposed to a cold period that will fulfill their vernalization requirement.

One must consider whether a variety can be overwintered in the ground under local conditions. If it cannot be overwintered in the ground and needs to be dug, having an appropriate space to store plants through the winter that will provide the right conditions is critical to successful seed production. Whether vernalized in storage or in the ground, biennial crops will also need to be given space in the garden to flower and develop mature seeds in their second growing season. The feasibility of pro-viding these conditions and requirements should be considered when selecting what crops and varieties to grow for seed.

When garden space is limited, a seed saver may want to bear in mind how much of the garden will be occupied by a particular seed crop. Decisions about what seed crops are worth the space they occupy may be influenced by the size of the plants at seed maturity, the recommended population size for maintaining a variety, and the length of time the plants will occupy valuable garden space.

Gardeners may also want to think about the availability of a variety from other sources and the amount of seed that can be collected from a harvest and used in seasons to come. For example, a gardener with a few raised beds may have a hard time allocating the necessary space to grow a kale crop to seed, even if a modest population size is used, because the plants are large and require relatively wide spacing. Kale also requires vernalization before flowering, so it occupies garden space for a longer period of time than most annual crops.

Additionally, many home gardeners grow only a few kale plants each season, and so a single packet of seeds will pro-vide enough seeds for several growing seasons at a modest price. In contrast, it is not uncommon for gardeners to grow dozens or hundreds of lettuce plants in a single season, especially if the crop is harvested as baby lettuce and succession planted. When one takes into consideration the prolific nature of lettuce plants (a single plant can produce more than a thousand seeds) and their relatively small garden footprint (lettuce seeds can be collected from a smaller population size, and plants can be spaced more closely together than kale), it might make more sense to routinely save seeds from lettuce, but to buy kale seeds every few years. However, if the kale variety is rare, and the lettuce cultivar is readily available, a gardener may choose to collect the kale seeds and purchase the lettuce seeds.

Although broccoli is commonly cultivated in vegetable gardens, it is difficult to bring to seed because flowering often occurs when temperatures are too high to support successful fertilization.

When the fruits or seeds are the edible part of a plant, additional space in the garden is not necessary when saving seeds. Provided they can be properly isolated, these crops are often ideal for saving seeds in smaller gardens. For example, seed savers can simply harvest a few properly isolated fruits from a planting of peppers being grown for eating and have seeds for many seasons to come. Although cross-pollinating crops, such as winter squash and melons, may require hand-pollination in order to produce true-to-type seeds and can take up plenty of space in the garden, they also work well for space-conscious seed savers because seed production occurs con-currently with crop production—the seeds can be collected from fruits that are harvested to eat.

The isolation requirement of a species or variety—and the amount of work it would take to provide it—is another consideration when selecting what to grow for seed. For all but a few strongly self-pollinating species, a plant’s mating system or pollination method needs to be taken into consideration to ensure that it produces true-to-type seeds. For cross-pollinating crops, isolation of a variety can be addressed by either meeting isolation distance recommendations or by managing pollination in some other manner.

When home gardens are located a sufficient distance from other gardens or farms, and seed saving is restricted to just one variety of a given species in a given year, isolation requirements can often be met for many cross-pollinated crops or those with mixed mating systems.

But when this is not the case, and isolation by distance is not feasible, the amount of effort needed to employ other controlled pollination methods should be considered. If a species can be isolated by means other than distance, such as with eggplant, which has flowers that are easily blossom-bagged to prevent unwanted cross-pollination, isolation distance may not be a limiting factor. When hand-pollination of some insect-pollinated species is possible, such as with pumpkins and squash, isolation can also be easily managed, although a seed saver may wish to consider how much time must be invested in the process.

On the other hand, spinach may not be a practical seed crop for some gardeners because it is a wind-pollinated species that requires a significant isolation distance, and it is not easily managed by alternative isolation methods. In addition, the recommended population size from which to collect spinach seeds in order to prevent inbreeding depression is large. All of these factors bear consideration when selecting crops from which to save seeds.

Featured Video

Recommended Reads

8 Seed Saving Myths

DIY Seed Bank: The Seed Series