Seed School, Part II

Seed saving is a tradition as old as civilization. It can even be argued that seed saving is in many ways responsible for civilization. The first European settlers to the Americas arrived with seeds in their pockets and the Native Americans were already growing and saving seeds here long before their arrival. There are stories of our founding fathers campaigning with seed packets bearing their faces at a time in our country when everyone saved and shared their seeds. There were no glossy seed magazines to order from, the seed industry as we know it was not yet born. If you grew food, you also grew, saved, and swapped seeds. We've nearly lost this cultural connection and have largely relegated this task to large-scale, industrial farming outfits and the biotech industry. We're too busy with more important things, right? Here is a snapshot of what that is costing us, taken from Bill McDorman's Basic Seed Saving:

"Much of the worlds agricultural genetic diversity took humankind 10,000 years to create. We may lose most of it in one generation. As late as 1900, food for the planet's hungry was provided by as many as 1,500 different plants, each further represented by thousands of different cultivated varieties. Today over 90% of the world's nutrition is provided by 30 different plants and only four (wheat, rice, corn, and soybeans) provide 75% of the calories consumed by man."



Reclaiming and sustaining our rich genetic heritage begins with learning to save seeds. I learned that it doesn't take a masters degree in genetics to do so. In fact, humans have been selecting seeds for edible crops for more than 10,000 years. Long before Gregor Mendel came along to teach us why it all works the way it does. Seeds, themselves, are 600 million years old and food plants are not natural in the sense that they spontaneously occur in nature. For example, all carrots originally came from Queen Anne's lace, all plants in the Brassica family (broccoli, cauliflower, cabbage, etc.) originated from the wild mustard plant, all corn originated as a grass called teosinte, and so on. Humans selected and saved seeds from the most desirable plants over thousands of years to bring us to the fruits and vegetables that we recognize and sustain ourselves with today. This method of basic plant breeding is known as recurrent mass selection.

GROWING AND HARVESTING

So where do we begin? Bill McDorman is the Executive Director of Native Seeds and was one of the brilliant instructors and facilitators of Seed School.  His book, Basic Seed Saving suggests that we begin with crops like beans, lettuce, peas, and tomatoes. These crops give us beginners the best chance of success for the following reasons: they are annuals, so they produce seed the same season as they are planted, and they are self-pollinating, which minimizes the need to isolate them to prevent cross-pollination. Plants that are not self-pollinating, like corn, spinach, carrots, Brassicas, etc.,  require a more controlled isolation zone to prevent cross-pollination. Their space requirements and methods of controlling cross-pollination are discussed in McDorman's book and in more thorough detail in a few references that I'll list at the end of this post. But for today, I'll stick to those for beginners. The first thing to consider is planting space.  Plants grown for seed do need a bit more space than those grown for consumption. A good rule of thumb is to double the spacing suggestion on the back of your seed packet if you are planing to grow for seed. Also keep in mind that seed crops need to be planted early enough in the season that they will have an opportunity to fully mature to their seed producing stage. As they are growing, you can select and rogue. Selecting means keeping the ones that seem hearty and viable, and roguing means pulling out the ones that don't seem desirable to keep for seed stock.

Lettuce grown for seed can be planted in the same bed with lettuce that you intend to eat. Just make sure if you are growing multiple varieties that will flower at the same time, you will want to space them at least 20 feet apart to prevent cross-pollination. If you don't mind a little variation in your final seed population, then don't worry about that step at all. Then, as your lettuce seeds sprout and grow, you can thin the rows and eat those as micro salad greens. As the remaining ones grow into fuller heads of lettuce, you can select and rogue again based on which plants are showing the characteristics you desire. The heads you rogue can then become dinner salads. Finally, you are left with the plants that you wish to grow to full seed maturity. Lettuce produces perfect, self-pollinating flowers. A perfect flower has both the stamens that produce pollen and the pistil, which receives pollen. It has everything it needs to self-pollinate, and will often do so before the flower even opens. Each flower on lettuce plant then produces one seed and the flowers are grouped into clumps of 10-25 flowers. Individual heads will ripen at different times, so rather than try to harvest large amounts of seed at once, you can wait until half of the flowers on one plant have gone to seed, cut the entire top off that plant, and allow it to dry upside down in an open paper bag for 2-3 weeks. Once they are dry, you can shake and rub the flower heads to remove any remaining seeds.



Peas and beans also contain perfect, self-pollinating flowers and they rarely cross-pollinate. They simply need to be left on the vine for their seeds to mature. Peas should remain for about 4 weeks past their eating stage, and beans for 6 weeks after their ideal eating stage. If a frost threatens, pull up the whole plant by the roots and hang it in a cool, dry place until the pods are brown. When they are fully dried, the seeds can be shelled out by hand, or for larger amounts, you can flail them. Flailing is the process of crushing seed pods in order to free the seeds. This can be done by hand, with flailing tools, or by a fun field method described in class. It begins by laying out a large tarp, laying a piece of plywood over the tarp, covering the plywood with a piece of chicken wire, then topping it all with the dried vines and pods. Grab a few friends and stomp the vines and pods thoroughly. Then, peel back the chicken wire like the page of a book, pulling all the vines and leaves off the top and leaving behind the seeds that have hopefully fallen through to the plywood below the layer of chicken wire. The tarp is there to catch any that try to roll away. This is not a perfect method, and the seeds will still need to be cleaned further, but it allows you to get rid of most of the messy vines and leaves before leaving the field.

Tomatoes are another great beginner seed to save. Most modern varieties only require about 10 feet of separation, but heirloom varieties will need significantly more space to ensure purity. Tomatoes, like beans, peas, and lettuce, are also self-pollinators, or "selfers" with perfect flowers. When growing tomatoes for seed, allow them to completely ripen on the vine before harvesting. If a frost threatens, you can bring them in to a cool, dry location to continue ripening. When they are ripe, simply cut them on the equator and gently squeeze out the seeds into a jar. The remaining flesh can be frozen, canned, dehydrated, or used in a tomato-based soup or stew.

Selecting seed from a number of plants is important to ensure you are collecting a genetically diverse sampling of seed from that particular type of plant. McDorman's book offers suggestions on how many plants to collect seed from to have good volume and increase your chances of having strong, viable seed. Always plant about a third more than you will need. You will be roguing out the less desirable ones, you will have some seeds that will inevitably not sprout, and once the seeds are harvested, you may need to discard any that are off-color or look unhealthy, so planting more than you need gives you a comfortable cushion.


PROCESSING

Once seeds are harvested, they are either dry-processed or wet-processed. Dry-processing means that the seeds are flailed, threshed, and winnowed. We already discussed flailing as the process of freeing the seeds from their pods. Threshing, then, is the process of separating the seeds from chaff. Chaff is made up of the tiny remnants of the seed pods or coverings. Winnowing is a method of removing the chaff, which uses wind (or a box fan, or your breath) to separate the lightweight chaff from the heavier seed. Flailing, threshing, and winnowing are all methods that can be done by hand and with minimal equipment, depending on the scale of your operation. You can purchase sieves, like the ones pictured below that are used by the folks at the Nasami Farm and Native Plant Nursery, or you can buy screens of varying gauges, or graduated stainless steel hardware cloth and make them yourself. Select a screen with an opening large enough to let the seeds fall through, while preventing the chaff from falling through. Never let lack of equipment get in your way. Be creative and use what you have on hand. Your equipment can be as low tech as an old window screen, or a three sided cardboard soda flat for winnowing and you can still have great success.

Some seeds, like squash or berries, require a wet method of processing. For squash, its as simple as
harvesting the mature seeds from your squash, placing them in a cup of water, pouring off the water and refilling several times, until you are left with clean squash seeds. Keep in mind that squash seeds are not often fully mature until the squash has nearly gone to mush. Leave them for several weeks past when you would normally harvest them for food. Then, harvest them, scoop out the seeds, wet-process them, and lay them out to dry. Once dried they may have a papery coating of chaff, which can be winnowed away. For berries, they may need to be crushed first. At Nasami, they crush the berries by hand or with a tool first, then pulse them with an immersion blender with a blade attachment that helps shake loose the seeds without damaging them. Then the remaining seeds and pulp are water winnowed by the same method described for the squash seeds. Generally, the good seeds will sink to the bottom and the rest will float to the top, so that each time you fill your cup and pour it off, you are left with cleaner seeds on bottom and clearer water until you can pour the final product through a strainer and all that remains is your seed.

Tomatoes are a simple seed to save, but require a unique process of fermentation to remove a gelatinous sac that surrounds each seed. This sac surrounding the seeds is important to prevent tomato seeds from germinating inside the warm, moist environment where they live. To harvest tomato seeds, cut the ripe fruit on the equator and scoop the seeds out into a jar. If the seeds in the jar aren't floating around in enough liquid, add a little non-chlorinated water. Place them uncovered in a window sill for a few days, until they have begun to grow a nice layer of fungus. This fungus eats the gelatinous coating and also produces natural antibiotics that help control seed-borne diseases like bacterial spot, canker, and speck. After three days, fill the jar with water and water-winnow the seeds using the same process described for berries and squash seeds. Each time you fill the jar, the viable seeds will settle to the bottom while the pulp and immature seeds float to the top, where they can easily be poured off. Once you have clear water with clean seeds at the bottom, pour through a strainer and lay them out to dry.

STORAGE

Once you have processed your seeds, you will need to consider how to store them. First, be sure that they are adequately dried. You can test this by trying to snap one in half. If it bends instead of snapping in two, it is still too wet. Another way to check is by inserting a fingernail into the seed. If your fingernail sinks in and leaves an impression, the seed may still be too moist. Seeds can be dried on screens, on paper bags, or on paint strainer bags. Paper towels are not ideal, since the seeds can sometimes get stuck to them. Most seeds require a cool, dark, dry place to be stored. Put them into plastic or muslin bags and label them clearly. Then, place the bags into air-tight glass jars. Canning jars work well. Keep in mind that the bags alone do not protect them sufficiently from moisture. Placing the jars in the refrigerator or freezer will work well, if you don't have another temperature, light, and humidity controlled environment. When you are ready to defrost, refrain from opening the jars until they have sufficiently warmed to room temperature. This will prevent condensation from accumulating on the walls of the jar and wetting your seed.

If you don't want to store them in the fridge or freezer, keep in mind that most seeds need to remain below 50 degrees. Absolute darkness is best, but storage is adequate if direct sunlight or bright artificial light is avoided. Humidity should be below 9% moisture. A handy rule of thumb offered by Rowen of the Sierra Seed Cooperative is that temperature and humidity, when added together, should total less than 100. She also suggested placing a desiccant pack, like silica gel, in the jar with your seeds to keep them dry. Some seeds, like those from tomato and squash, can remain viable for 10 years if stored properly. This is good news for a small grower like myself that may not have the physical garden space be able to generate enough seed in one growing season. I can save the seeds from my best 4 or 5 squash plants, store them well, then do the same the following year, I will begin to accumulate a decent and diverse stock of that particular seed.

The importance of good record keeping was stressed over and over throughout seed school. Keep a notebook on hand to record important information throughout your growing, harvesting, and storage process. Make notes about which varieties succeeded, which ones did well during inclement weather, which ones resisted bolting, or resisted disease. Note the number of days it took for a plant to flower and produce seed, note your successes and failures in harvesting and cleaning the seed. Which gauge screen worked well, which speed your box fan was on for winnowing, and so on. Finally, make sure to label all of your stored seed. Label them on the bag and on the outside of the jar, that way if one label gets damaged or lost, you still have a backup.


ADDITIONAL RESOURCES

Bill McDorman's Basic Seed Saving, provides an excellent overview and is broken down into beginner, intermediate, and experienced categories. You can purchase a hard copy, or download a pdf here. If you are interested in digging deeper and want more detailed information about isolation requirements for certain crops, or if you want to move beyond the basic recurrent mass selection breeding model and get into more controlled and selective breeding, check out Rowen White's book Breeding Organic Vegetables. Rowen's mentor, John Navazio, wrote The Organic Seed Grower, which comes very highly recommended. The founder of Native Seeds, Gary Nabhan, has a fabulous book called Enduring Seeds. Matthew and Petra of Fruition Seeds have some really handy videos on their website that show how to clean, process, and save a variety of seeds that you can check out here. Also, keep in mind that there are seed saving clubs and seed swaps taking place all over the map. If you find one in your area, you may be able to connect with a whole network of local friends who are willing to share their knowledge and locally adapted seeds with you.


Good luck and happy seed saving!