the seed garden pam dawling
TRANSCRIPT
The Seed Garden Planning for seed saving
and lots of vegetables to eat
©Pam Dawling 2016 author of Sustainable Market Farming www.sustainablemarketfarming.com
www.facebook.com/SustainableMarketFarming
What’s in this presentation 1. Growing seed crops alongside vegetable production 2. Which seed crops combine best with food production? 3. Selecting and marking for variety improvement 4. Wet seeds and dry seeds 5. Seed crops we grow in the Twin Oaks vegetable garden
1. Roma paste tomatoes 2. Crimson Sweet watermelons 3. Okra 4. Flowers
6. Using the summer hoophouse for seed growing 1. Cowpeas 2. Edamame 3. Other dry beans 4. West Indian gherkins 5. Leaf beet
7. Population size 8. Isolation distances 9. Seed drying and cleaning, storage and germination testing
Growing seed crops alongside vegetable production
Fit seed growing into your vegetable production schedule - seed crops have a longer, slower season and a less pressured pace most of the year. (After all, while the stuff is growing, you don’t harvest till the seeds are ripe.)
Diversify your sources of income.
Earn some money during the winter, when seed companies test seed deliveries and pay (and produce sales are down).
Keep good Open Pollinated seed varieties alive and available.
Support small inter-dependent seed companies in the face of Monsanto.
Improve a variety to best suit your climate and your customers.
Improve a variety to be more tolerant to a disease or a pest.
Which seed crops combine best with food production?
Because our main focus is food production, we do our seed saving in a way that fits in with getting maximum food as well as seeds. Crops where we eat the ripe fruit take very little extra time to
mature seeds — just make sure the fruit is really ripe. You still get to eat or sell the food crop.
Crops with harvests either at the end of the main season, or every week in August (avoid crops that come in all at once in the summer)
Crops that naturally do well in your area Crops where you really want to increase the seed availability Crops which will grow without much attention in spaces you are not
using that season, eg high summer in the hoophouse. You may already be doing some small-scale seed saving, or perhaps
saving clones of vegetatively produced bulbs. Like most garlic growers, you may save your own seed garlic, as we do. Or yellow potato onions or shallots for replanting. Or peanuts.
Double benefits • In some cases, your crop could produce both food and seed, as we do with our
tomatoes and watermelon.
• Getting two crops from one plant does take more time, compared to simply mashing the whole tomatoes, for instance.
• Other ways to have your crop and eat it too:
– Harvesting a few leaves from greens grown for seed will not detract from seed production.
– Eat the produce from the edges of a block planting and save seed from plants in the center — this helps preserve the purity of the seed without “wasting” the edge plants.
– Eat the earliest fruit and save seed later, or save seed first and eat the later fruit. Seed should not be saved from plants past their prime, however, and you would not want to risk your seed crop by reducing the time it has to mature by too much.
• You may be able to grow seed for flowers that attract beneficial insects or pest-eating birds to your crops.
• Keep records of your dates, as the timing might get critical and some crops will work better than others.
What type of crop to grow? • Choose an open-pollinated variety of the crop you want to grow.
Hybrids, which are produced by deliberately crossing two genetically different varieties, do not “run true” — that is, seed saved from hybrids produces very mixed progeny.
• Choose a crop you can easily grow to maturity in your climate. In your first year, avoid unfamiliar crops, biennials or too many different seed crops.
• Choose something you only grow one variety of, or can easily grow far enough from others. Photo Bridget Aleshire
• Choose something your neighbors don’t have growing the other side of your fence line!
• Choose something that interests you. Maybe you’d love to see a host of orange cosmos flowers brighten your vegetable field!
• Self-pollinated crops often have good open-pollinated varieties, so they are a good place to start.
Food for thought • Not all fruit crops can
provide both food and seeds at the same time. Cucumbers are eaten as under-ripe fruits, and the seed is mature when the cucumber reaches the yellow blimp stage.
• Photo Twin Oaks Seed Farm
Biennial plants • Biennials (such as onions, carrots,
most other root crops) need a second growing season to mature seed. Some may be left over winter in the field, others are replanted in spring.
• In the second year the flower heads and seeds will form.
• Leaving the roots in the ground over the winter is easier, but if your climate gets very cold, or fluctuates a lot (ours does), or if you have lots of voles (we do), then digging the roots and storing in a cool, damp root cellar is wiser. It also gives you the chance to select well-shaped roots as your seed stock.
Photo Small Farm Central
Starting small • You could start by growing one or two seed crops for yourself. This is
a valuable project, as you can select plants that grow especially well under the conditions on your farm, as well as save on seed costs. Read up about seed growing.
• It’s possible to sell your seeds directly by joining Local Harvest and selling on their website, where there are over a thousand entries on seed for sale. You can create a free listing with http://www.localharvest.org/ if “You are a direct marketing family farm that does not grow GMOs, a producers’ farmers’ market, a business that sells products made from things grown locally by family farms, or an organization dedicated to promoting small farms and the ‘buy local’ movement.” Even eBay now has heirloom seeds!
• USDA Certified Organic seed is much in demand, but uncertified sustainably/ecologically grown seed also has a market, especially for heirloom or heritage varieties.
Expanding seed growing • Most seed growers continue to grow a mix of crops — a seed crop,
like any other crop, could fail.
• But if seed growing really suits you, you could move more towards growing seeds and away from other crops.
• When you are ready to grow a commercial seed crop, contact seed companies before the start of the season to agree on a contract.
• Some seed crops (okra, winter squash) can sit around for a while drying, with no particular hurry.
• Others will need more immediate attention.
How much to grow? How much space? How long will it take?
• Never save seed from just one plant (unless it’s the second to last on the planet). Grow a big enough population of plants to keep enough genetic diversity for future adaptability and to prevent a genetic “bottleneck.”
• Inbreeding depression occurs when seed is saved from too small a planting. It leads, over time, to lower quality, less vigorous plants. To avoid it, cross-pollinators need a bigger population.
• There is, as yet, no published table of time from sowing to seed crop maturity. Lettuce can take up to 2 months beyond the eating stage to get to the mature seed stage (See Fedco’s charming Activity Guidebook in the Living Tradition of Seed Saving, Eli Kaufman http://growseed.org/GenerationtoGenernation.pdf )
Flowering lettuce
Selecting “mother plants” • If you are selling seed, you will need more plants
than if you are just keeping seed to resupply yourself.
• You have a responsibility to maintain that variety and all the genetic diversity it contains.
• Grow enough to allow for rogueing if you are maintaining a variety for a seed company. Rogueing involves removing off-type plants as well as existing fruits from the immediate neighbor plants.
• Also rogue out diseased plants and any early-bolting plants of crops you don’t want to bolt.
• If you are improving a variety, selecting for certain desirable traits, you will be even more selective about choosing good mother plants.
• Photo Wren Vile
Selecting and marking for variety improvement • As our tomatoes ripen, we monitor
the plants, marking ones with healthy foliage and ones yielding very well.
• We use flagging tape (plastic or crepe paper marking tape): green or yellow to show healthy foliage with OK yield; red for abundant fruit with OK foliage (the best plants get 2 ribbons!).
• We tie tape on the T-post next to the chosen plant, with the bow or knot on the side of the post facing the plant.
• We do this once a week, on the day before the crew comes through to do a harvest (no good looking for high yields when they’ve already been picked!)
Flagged Roma plants. Photo by Kathryn Simmons
Biodegradable flagging tape
3.0 mil Nonwoven Cellulosic Roll Flagging $2.60 from Ben Meadows
Presco Biodegradable Flagging Tape is made of material derived from wood pulp. Degrades in 6–24 months (depending on conditions). Completely nontoxic.
http://www.benmeadows.com PRESCO Biodegradable Flagging Tape - 36814365
Numbering watermelon
Mark chosen watermelons using a grease pencil. Photo by Nina Gentle
Wet seeds and dry seeds Wet seeds Dry seeds
Beans, okra, corn, radish
Dry seeds are found in pods, husks or ears, and dry down on the plant. Dry seed processing involves harvesting the pods or the entire plants, completing the drying indoors if needed, then cracking or breaking the pods to release the seeds.
Tomatoes, cucumbers, melons, eggplant Wet seeds are embedded in the fruit. Wet processing has several steps: scooping out the seed or mashing the fruit, fermenting the seed pulp for a few days, washing the seed and removing the pulp and then drying the washed seed. Wet-processed seed is naturally cleaned during the fermentation and washing.
Seed crops we grow in the Twin Oaks vegetable garden
• We grow, select and save seed from paste tomatoes, watermelon, edamame, cowpeas, gherkins, okra and some flowers grown to attract beneficial insects (cosmos seed is very easy to collect).
• From time to time we also save seed from other crops, if a need or an opportunity presents itself.
• West Indian gherkins. Photo Nina Gentle
Roma paste tomatoes • We grow Roma paste tomatoes because we make a lot of
sauce, juice and salsa, but for years our yields were much reduced by Septoria leaf spot.
• There didn’t seem to be any commercially available Septoria-resistant variety when we looked, so I decided to develop our own resistant strain.
The reward for developing a strain of Roma that is resistant to Septoria is of great value to us – healthy plants for a long season. Photo Southern Exposure Seed Exchange
Planting our Roma tomatoes
Roma tomatoes with Florida stringweaving. Photo Bridget Aleshire
Tomatoes are self-pollinating, so planting 200 or more, pulling out any off-types, and making a selection of 80–100 of those plants gives plenty of genetic diversity. We put out our 250 transplants as usual, two feet (60 cm) apart in late April or early May. We make sure when we plan our plot layouts that we don’t put any tomato plants of any other varieties within 180 feet (55 m) of any of our Romas. We use the Florida string-weave system, with a metal T-post after every two plants and a new round of twine each week.
Harvesting our Roma tomatoes • After 1-2 weeks of monitoring and flagging, we start picking for
seed, on those same just-before-bulk-harvest days. • Our method combines well with crew harvesting most of the fruit
as food. • If you are growing the variety only or mainly as a seed crop, you
would save all the seed from the chosen plants, or from the whole row after pulling out any unpromising plants (“rogueing”).
Harvesting Roma tomatoes. Photo Twin Oaks Community
Harvesting for seed • We assess the flagged plants and
take ripe tomatoes from each plant that has both green and red flags, or has one flag and is not worse than average on the other factor.
• If the plant no longer looks so great, we remove its ribbon.
• If a plant without a ribbon starts to excel in healthy foliage as the season wears on, we add a ribbon.
• We don’t add many red ribbons after the start of the harvest, because we want to keep selecting for early fruit, and plants that yield well later are not what we want.
Photo by Raddysh Acorn
Extracting the seeds • We usually pick about 5 gallons (19 L) for seed each week. We store those
buckets of tomatoes in a secret location, where no one will eat them, for 5 days, which lets the fruit get completely ripe. We cut the dead-ripe fruits in half, rejecting any diseased ones. This photo shows larger scale harvests.
• Next, we scoop out the seeds with a tablespoon. This lets us use the “shells” for tomato sauce for our own use.
• The seeds ferment in the bucket in a shed for 2-3 days, nominally at 70°F (21°C). We stir 2 or 3 times a day.
Photo Twin Oaks Seeds Farm
Washing the tomato seed • When fermentation is over (no more
bubbles), we take several clean buckets and a sieve and wash the seed clean. This art gets easier and quicker with practice. The good seed sinks to the bottom.
• Pour off the top half of the ferment (mostly no good) into another bucket.
• Add water to both buckets, stir, let things settle and then pour off the tomato pulp and no-good floating seeds from both.
• Consolidate the better stuff in one bucket, the worse stuff in another, and pour away the water. Add more water and repeat several times.
Washing a seed ferment. Photo Twin Oaks Seeds Farm
Tomato seed drying • Once the seed is clean, strain it
through the sieve and spread to dry with a fan, on a window screen or paper towels.
• After 6-12 hours, scrape the clumps of seed off the surface with a putty knife, turn them over and crumble the clumps by hand. After 2 days, once the seed is thoroughly dry, gather it into a paper bag and add some desiccant.
• We hold back on storing in an airtight container until we’re absolutely sure the seed is dry. (More on Storage later.)
Fitting tomato seed work into our schedule
• Here’s how we fit it together in an efficient, easy-to-remember way:
– we harvest seed on Monday
– scoop on Friday, which is the day the Food Processing crew are making sauce.
– we start the fermentation on Friday, wash on Monday, set those seeds to dry and harvest the next batch.
• We usually do 4 or 5 batches of seed, during August. It’s not good to save seed from plants in decline, so get started as soon as you can, and quit while the going is good. We sell this seed to Southern Exposure Seed Exchange.
• 20 gallons (76 L) of Roma tomatoes makes 130 gm of seed.
Crimson Sweet watermelons • We started growing Crimson Sweet watermelon seed because
we wanted larger earlier melons.
• I’m also hoping that by never introducing other watermelons into our gardens we can avoid seed-borne Watermelon Fruit Blotch Disease.
• Photo Southern Exposure Seed Exchange
• We had a long way to go, improving early ripening of our watermelons, because we had been using hay mulch for weed control, which cools the soil, delaying ripening!
• We now use the biodegradable black plastic mulch (Bio Telo Mater-Bi — we’re not USDA certified, so the fact that it is not yet OMRI listed doesn’t matter). This change alone gives us melons almost four weeks earlier than when we used hay.
Watermelon on bioplastic
Watermelon growing on biodegradable plastic mulch. Photo Nina Gentle
Selecting and marking watermelons • We have already started selecting healthy plants when transplanting
• In the middle of July, as the melons ripen, I walk through the plot with a grease pencil (china marker) and number selected melons.
• I look for big melons with vigorous healthy vines. I select 30-40 to melons. Cucurbits, although cross-pollinators, show relatively little inbreeding depression, and a population of 25 plants will be enough. Crew are told not to ever pick any melons with numbers on.
I’ve tried other ways to mark melons (flags, magic markers) but the grease pencil works nicely. Having a big number right there on the skin of the melon works to stop any crew about to harvest it. Photo Nina Gentle
Larger scale watermelon seed harvest Twin Oaks Seed Farm
Watermelon seed harvest • Once a week I harvest for
seed, taking melons that are very ripe and discarding any that don’t look healthy.
• I like to only deal with 6 to 8 melons each time. I keep notes of which numbers I harvest each week, and assess them for size, ripeness and, once I open them, taste.
• I take a big knife, several clean buckets and a big spoon (and a damp cloth — it’s messy!). I cut the melon across the middle and taste from the heart. If I don’t like the taste, I don’t save seed from that one.
Scooped–out Crimson Sweet shells. Photo Kati Falger
Watermelon seed harvest
• It can get hard to find all the numbered melons (that’s where the notebook comes in handy, so I don’t waste time looking for one that I already harvested).
• I abandon any numbered melons that don’t ripen early, and I sometimes add any huge melons that pop up after the initial numbering.
• Earliness is important to us, though, so I only harvest four or five times and then stop. For us that’s an August task.
Crimson Sweet watermelon. Photo Nina Gentle
Photo Twin Oaks Seed Farm
Watermelon seed harvest • If the taste is good I scoop
out the heart, which is seedless, into a very clean bucket, for eating later. Then there is a layer that is thick with seeds. I scoop this into the seed bucket.
• Lastly I scoop the outer flesh, also relatively seed-free, into the food bucket. The scooped-out watermelon flesh makes great smoothies and sorbets.
Crimson Sweet quarters. Photo Southern Exposure Seed Exchange
Watermelon seed fermenting
• These seeds get fermented for about four days, then washed similarly to the tomato seeds and dried.
• For example, if I harvest and scoop on Tuesday, I wash on Saturday and set the seeds to dry for several days.
• One Crimson Sweet watermelon yields 22 grams of seed; 22 melons yield one pound of seed.
Fermenting cucurbit seeds Photo Twin Oaks Seed Farm
A method of straining seed ferments Twin Oaks Seed Farm
Okra • We only grow one kind of okra
(Cow Horn — it gets big without getting tough), and nothing that would cross with it.
• Saving seed is just a matter of flagging choice pods on good sturdy plants, and letting those pods ripen.
• It’s true that leaving pods or fruit on a plant to ripen will decrease the yield of food from that plant, so it is important to balance your goals and not lose your cash crop for the price of a small packet of seeds.
• Cow Horn okra. Photo Kathryn Simmons
• We collect them before they shatter and dry the seed in a mouse-proof place. It’s a large seed, and the dry pods shatter easily, so it’s simple to separate the seed from the pod pieces. And we don’t need a lot of seed, so it’s not a major undertaking.
Cowhorn okra, flagged. Photo Raddysh Acorn
Marking Cowhorn okra
Flowers • We plant “islands” of flowers to
attract beneficial insects to our vegetables. Some of these flowers have very easy-to-collect seeds.
• Cosmos, French marigold, calendula and dill can all be left growing until dry seeds appear in their heads. These can then be rubbed off into a paper bag.
• Clearly this way of growing seeds uses only a small population of each plant, so seed saved this way cannot be sold, but it is fine for home use for vegetable growers doing a bit of farmscaping.
Insectary circle. Bridget Aleshire
Sunflowers • We like to grow sunflowers throughout our vegetables, and
sometimes we save seed from those. It’s best to leave the developing head on the plant as long as possible, so that it dries down well and the seed fully matures.
• The trick is to keep the birds off. Our answer is to tie a bandana over the head, knotted at the back. You can decorate your garden with red and blue bandanas, or find color-coordinated fabrics.
• When the sunflower stalk dries out, remove the seed head and complete the drying in a place protected from mice.
Photo Bridget Aleshire
Using the summer hoophouse for seed growing
• Summer legumes make a great class of summer hoophouse crops (either as produce or as seed crops).
• Where it is humid or rainy, it is hard to grow dry seed crops such as legumes, lettuce, spinach and beets (as opposed to “wet” seed crops inside fruits, like tomatoes, melons, peppers, squash and cucumbers) outdoors, but using covered space opens new possibilities.
Mature cowpeas in the hoophouse. Photo Wren Vile
Hoophouse seed crops • Inside a hoophouse the hotter air
can hold more water without causing damp plants. The hoophouse walls also provide a partial physical barrier to prevent cross-pollination.
• Compared to outdoor crops in our climate, legumes grown in the hoophouse have very clean, unspotty beans and pods.
• Ira Wallace suggests that biennials such as carrots or onions for seed can be interplanted in a hoophouse with overwintered greens. As the biennial plants start to grow bigger, remove the early spring greens and let the seed plants grow. Edamame pods in the hoophouse.
Photo Raddysh Acorn
Cowpeas • We sow in mid-June-mid-July, when
we pull up our early warm-weather crops such as cucumbers, early tomatoes and squash. We can harvest to eat in late September through early October. The seed crops mature in late October or early November, just when we want to transplant our winter salads and greens.
• Cowpeas can be sown later than they would be outdoors, to provide seed or dry soup beans in early November.
• We tried a July 27 sowing, but it was a bit too late — we didn’t harvest much.
A 7/25 sowing of Carolina Crowder peas in our hoophouse. Photo Nina Gentle
Cowpea string-weaving cats cradle
How we support the cowpeas in our hoophouse. Photo Nina Gentle
Edamame
• Edamame does particularly well in our hoophouse.
• Growing it under cover means we get beautiful pods (an important feature for edamame!).
• An advantage of this crop it is that is picked all at once — take it from me that you do not want a crop that requires daily harvesting in high summer in your hoophouse, unless you live in the Far North.
• We like Envy edamame, a short bush type that matures quickly. We sow July 27 and harvest Oct 4–13, or Nov 9 for seed. Maturing edamame pods.
Photo Twin Oaks Community
Shelling beans or soup beans • Shelling beans or soup beans have given good results in the
hoophouse.
• We grew King of the Early, sown July 13 and harvested from late September until mid-October, when we let the last pods dry out for seed.
• We’ve found that we don’t like putting up big trellises, so we now choose bush type beans. Bush varieties also allow the sunlight to better reach the north side of the house.
Growing bean seed • Most bean species are largely self-pollinating, so you
will likely have pure seed with 100 feet (30 m) isolation distance, or barrier crops of flowers to distract pollinators.
• According to Nancy Bubel, in The Seed Starter’s Handbook, bean seed is ready when your teeth can scarcely make a dent in a sample bean. Maturing happens fast in a hoophouse.
Mississippi Silver cowpeas in our hoophouse. Photo Twin Oaks Community
West Indian gherkins
• I first saw these unusual pickling cucumbers at Monticello. The origin of the variety is uncertain, but the seed was probably brought to Virginia by people enslaved by Thomas Jefferson.
• West Indian Gherkins are very heat tolerant and disease resistant.
• They are resistant to Peanut Root Knot Nematodes, which is why we started growing them.
Photo Nina Gentle
West Indian Gherkins • These gherkins do not cross
with regular cucumbers, nor with watermelon (although the leaves resemble watermelon leaves)
• We trellis them in our hoophouse (they are very sprawling long vines, left to their own devices.)
• We harvest one end of the row for pickling and one end for seed
• We sow 3/31, transplant 4/21, harvest picklers starting 6/12 and pick the seed crop 9/28 – 10/2.
• Photo Bridget Aleshire
Leaf beet
• Leaf beet or Perpetual Spinach, is a type of chard.
• When seed was unavailable one year, I dug up a few outdoor leaf beet plants in the fall and replanted them in our hoophouse.
• Leaf beet is biennial, so in the spring tall flower stalks grow up and make seed.
• For better seed growing, a bigger population of plants would be needed to guarantee genetic diversity.
• The second year that I did this, I learned a trick of beet seed growing:
• Cut down the first tall stems that appear and you get many more flower stems, at a shorter height — two advantages: more seed, less stem.
• An unexpected benefit was the wonderful smell of the flower heads!
• Photo Southern Exposure Seed Exchange
Population size • Be sure to have a large enough population of plants to ensure a
diverse genetic pool. • With self-pollinators (inbreeders) such as beans, 20 plants may be
enough - self-pollinated varieties are already genetically quite homogenous, and there is little gain from a bigger population.
• For out-breeders (cross-pollinators) you need at least 100 to avoid inbreeding depression. Large plant populations are needed to maintain genetic diversity.
• Hybrids of cross-pollinators such as corn exhibit “hybrid vigor” (meaning hybrids undeniably have an edge as far as productivity goes), but hybrids of self-pollinators don’t show this trait as much.
• While experienced seed growers can develop stable strains from a hybrid, this requires years of work and is not the place to start.
Isolation distances • The isolation distance required for a particular species depends on whether
the plants are self- or cross-pollinated.
• Self-pollinators use their own pollen to set seed, without any transfer of pollen from other plants. Because avoiding unwanted cross-pollin- ation is not an issue, isolation distances are smaller.
– Tomatoes (selfers) mostly self-pollinate, and only require an isolation distance of 75 to 180 feet (23–55 m).
• Cross-pollinating (outcrossing) plants may be wind- or insect-pollinated. It is important to prevent unwanted pollen (from compatible plants other than your seed crop) reaching your crop. Isolation distances (from other crops which could pollinate your crop) are large.
– Bees fly a long way, so cucurbits (crossers) have long isolation distances of 1,500 feet (460 m), or even as much as half a mile (800 m) if you have no physical barriers.
• Wind-pollinated crossers usually have the most genetic diversity and pollen that travels furthest, so they need the longest isolation distances.
Ways to improve isolation • Barriers such as buildings, including hoophouses,
and tall crops - corn or sunflowers, can help a borderline isolation be more certain, especially for insect-pollinated crossers.
• Collect seed only from the middle of a planting block, rather than at the edges.
• If you are determined to get seed of a particular crop, use advanced tricks - bag, cage, hand pollinate.
• Observing isolation distances can restrict what you can grow for food, but if your growing season is long enough you may be able to have a zucchini crop for early market, then sow pumpkins for seed, and ruthlessly pull up the zucchini before the pumpkins flower.
• This food-then-seed system is known as isolating by time.
• If your season is long enough and the crop maturity quick, you could grow two seed crops.
Photo Bridget Aleshire
Negotiating isolation distances with neighbors
• Once you know the required isolation distance for the crop you plan to grow, make sure your planting map gives you this space.
• Early each year we write a “Seed Saving Letter” to others who grow plants in the area, to tell them where we plan to grow our seed crops, and asking them not to plant anything that could cross-pollinate with that crop within the isolation distance.
• In return, we offer our surplus transplants, and we also ask them if they have any seed saving plans we need to know about.
• We grow the same dill variety in our insectaries as the Herb Garden grows for dill seed. We plant our flashy calendula far away from the medicinal ones.
• Some cross-pollination can still occur with selfers.
Seed drying and cleaning • Wet processing has 4 steps: scooping out the seed or mashing the
fruit; fermenting the seed pulp washing and drying the seed. The challenge is to ferment the seed long enough to release the clean seed, without waiting so long that the seed starts to sprout.
• Dry seed processing involves harvesting the pods or the entire plants, then cracking or breaking the pods to release the seeds. Surprisingly, hoophouses with shade and good ventilation can be good places to quickly dry seeds. After drying, the seeds and chaff are sieved through 2 different gauge mesh screens: the larger one keeps back the big chaff and lets the seed pass through; the smaller one keeps back the seed while letting the small chaff pass through. After screening, the seed is winnowed, using a box fan and a sheet of cloth or a plastic tub to catch the seed.
• While small quantities of seed can be cleaned with basic kitchen equipment, if you move into larger quantities, you will want to buy some of the specialized equipment available, or make your own.
Seeds drying on screens. Photo Twin Oaks Seed Farm
Storage • Make sure your storage places are mouse-proof.
• Initial storage can begin when seeds are down to 8 percent moisture. At this level, seeds break or shatter when you try to fold them or hit them with a hammer. They don’t bend or mash.
• Put them in a jar (optionally with an equal weight of a desiccant such as silica gel) for 7 days. For USDA Certified Organic, check the OMRI list before using desiccant - only use allowed materials.
• Then remove the desiccant and put seed in a labeled bag inside a labeled glass or metal container with an airtight lid. Seeds must be stored dry and cool and airtight once dry.
• For long-term storage, put your airtight jar or can in the freezer.
• When removing seeds from the freezer, allow the container to warm to room temperature for a day before opening. This prevents moisture from condensing on the seeds.
Germination testing • To find out how well your seeds will do, test their germination. Take a
thick paper towel, fold it lengthwise, unfold it and spread fifty or a hundred seeds along the inside of the fold. Close the fold, dampen the towel with water and roll it up loosely. Put it inside a loosely closed plastic bag and set the bag somewhere at a suitable temperature; often the top of the fridge is suitable.
• Beware the top of water heaters that use natural gas: this inhibits tomato seeds and other nightshades. 75°F (24°C) is good for most vegetables, 80°F (27°C) is better for tomatoes and peppers, 85°F (29°C) for melons.
• See Nancy Bubel, Seed Starter’s Handbook, for ideal temperatures for different crops.
• Check twice a day (the air change will help the seeds even if you know it’s too early to see sprouts).
• Count the number of sprouted seeds after 7 days and remove the sprouted ones.
• Repeat after another 7 days and add this count to the first one to calculate your percent germination.
Seed Saving and Plant Breeding Resources The Seed Garden, Micaela Colley and Jared Zystra, Seed Savers Exchange, 2015
Seed to Seed, Suzanne Ashworth, 1991, ISBN 0-9613977-7-2
The Seed Savers Handbook, Jude and Michel Fanton, 1993, ISBN 0-646-10226-5
Back Garden Seed Saving: Keeping Our Vegetable Heritage Alive. Sue Strickland, 2001. ISBN 978-1899233090
Vegetable Seed Production, Raymond A.T. George, 1999
Seed Production: Principles and Practices, Miller McDonald & L. Copeland, 1997
Breed Your Own Vegetable Varieties, Carol Deppe, 1993, ISBN 0-316-18104-8
Organic Seed Grower, John Navazio, Chelsea Green, 2012, ISBN 9781933392776 http://www.chelseagreen.com/the-organic-seed-grower
Diseases and Pests of Vegetable Crops in Canada, Ed. Howard, Ronald, 1994, ISBN 0-9691627-3-1
Principles of Plant Breeding. 2nd Ed. R.W. Allard, 1999.
Seed Starter’s Handbook , Nancy Bubel,
Knott’s Handbook for Vegetable Growers, 5th Edition, Donald Maynard, 2006, ISBN: 978-0-471-73828-2 Widely available online http://extension.missouri.edu/sare/documents/KnottsHandbook2012.pdf
Online Resources Seed production manuals from www.seedalliance.org/index.php?page=Publications Principles and Practices of Organic Bean Seed Production in the Pacific Northwest Principles and Practices of Organic Radish Seed Production in the Pacific NW Principles and Practices of Organic Spinach Seed Seed production manuals from www.savingourseeds.org/growguides.html Isolation Distances Seed Processing and Storage Bean Seed Production Brassica Seed Production Cucurbit Seed Production Pepper Seed Production Tomato Seed Production Organic Seed Alliance OSA has free downloads of crop specific seed production
manuals, other seed related publications, organic seed advocacy information and news. www.seedalliance.org
Organic Seed Resource Guide eXtension.org http://www.extension.org/article/18340
Saving Our Seed SOS offers several publications on seed saving available for download online. http://www.savingourseed.org/pages/ResourceGuide.html
Activity Guidebook in the Living Tradition of Seed Saving, Eli Kaufman http://growseed.org/GenerationtoGenernation.pdf
The Seed Garden Planning for seed saving
and lots of vegetables to eat
©Pam Dawling 2016 author of Sustainable Market Farming www.sustainablemarketfarming.com
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