Seed Saving Tips with Sarah McCamant, John Navazio, and Matthew Dillon
Since the birth of agriculture, saving seeds has been basically second nature for most of humanity. In our modern world, however, many of us aren’t even minimally conversant in the act of growing and harvesting our own food, let alone well versed in how to select and save seeds. Luckily, there are resources in our community we can turn to for guidance. In this transcribed conversation from a workshop at the Bioneers Conference, three expert seed savers share their best practices and discuss the implications and deeper meaning of seed saving in the modern era.
John Navazio, Senior Scientist for the Organic Seed Alliance and a Plant Breeding and Seed Specialist for Washington State University Extension.
Matthew Dillon, Director of Agricultural Policy & Programs for Clif Bar & Company and the cultivator for Seed Matters, an initiative of Clif Bar Family Foundation
SARAH McCAMANT: Know Your Seed, and know what you’re planting.
Make a label and remember what it is. You need to know whether it’s a hybrid or an open-pollinated variety, because when you save seed from hybrids, they do not grow true the next year. You’re going to get some other version, and probably end up trying to figure out why your Sun Gold tomato doesn’t look like a Sun Gold tomato the next year because it was a hybrid. So you’re looking for open-pollinated varieties.
Hybrids either say “great new hybrid” in their description, or they say F1, which means it’s the first generation of a cross. People do save seeds from hybrids, but I’m not going to encourage that because it is a breeding project, trying to stabilize a new variety and bring it back to being open-pollinated. John, how do you describe open pollinated?
JOHN NAVAZIO: Really, in botanical terms, it means that it’s freely allowed to pollinate with other plants of that same variety within that group of plants that you’re growing when you’re growing them. So in some cases we have “selfers”, which are actually selfing, but it essentially means that it’s not a controlled pollination, which is often what the seed companies are doing, especially with hybrids.
Essentially we’re talking today about annual and biannual plants. Annuals are very easy to think of because they complete their entire reproductive cycle, their complete life cycle, within one season. So you plant them in the spring, they go through summer, they flower, they make seed, and then all annuals die at the end of one growing season.
As a seed saver with annuals, the thing to think about is how much variation is there in the time of flowering between the varieties of a crop. We’re based in Washington State, almost to the Canadian border, and we work with northern farmers all the way to northern Alberta, Maine and Quebec. So time to flowering and then being able to plant that crop early enough so it fully matures seed is very crucial. And even for you here in paradise, here in California, where you have a much more lengthy season, there are still some things that I’m sure do not fully mature in this climate. So that’s one of the things you have to be conscious of before you get into full blown seed saving.
And in some cases you need to be conscious of, gee, I have a lettuce, but I don’t want it to flower too early; I want it to be in the vegetative stage for long enough. So you start to play with the timing of this crop in its vegetative versus reproductive stage. It gives me a nice lettuce for a few weeks of harvest before it flowers, and then still matures in time to give you a full satisfying seed crop.
MATTHEW DILLON: I want to add that it’s not just about the seed crop being able to get to maturity, it’s also about being able to harvest the seed crop before the rains come in. Brassicas, kales, broccolis, mustards, lettuce, and spinach are all dry-seeded crops as opposed to wet-seeded crops like tomatoes, cucumbers, melons that you’re harvesting from the flesh of a fruit. In dry-seeded crops you not only want maturity, you want to make sure that you’re going to be able to get that seed off the plant before moisture puts that seed at risk of fungal diseases, or of even sprouting on the plant. Sometimes lettuce that starts to seed will sprout while it’s still in the flower head. So it’s not just about maturity before cold comes, it’s also about maturity and harvestability before adverse weather sets in.
JOHN NAVAZIO: Let’s go ahead and define biennials. Biennial means two seasons of growth to complete the life cycle. It’s amazing how many garden plants are biennials. The great advantage of being a biennial from the plant’s perspective is that it stores sugars in one form or another during the first season of the life cycle, so that then when the second season comes, it can put all of that stored energy into a large amount of seed. Swiss chard, for example, stores a lot of food in their leaves; cabbage is another example of that. Biennials, on a plant-for-plant basis, tend to produce much more seed than the annuals do because of this effective plant strategy.
So the defining thing about biennials that many people growing them don’t really realize is that they require something called “vernalization”, which means it takes 8-10 weeks of temperatures at or below 50 degrees before they flower. Many of these plants evolved in semi-temperate or sub-tropical regions where in winter they can survive being outside without being completely frozen, as would happen in further north regions of temperate zones. They survive during the winter, but they go through enough cold so it essentially signals to the plant that it is safe for them to start growing again and go into the reproductive phase. So when you have biennials that flower during the first season of growth, you should never save seeds from biennials that flower during the first season. It means they’re prematurely flowering.
Even in San Juan Bautista the other day, we were in a Swiss chard trial where plants had been planted in late June and some of them were flowering. Very undesirable. Don’t think, Ah, this is great, I don’t have to go through all that waiting all winter and going through vernalization, I can get my seed now. You will be selecting for an annual cycle on that plant.
Cabbage is one member of the brassica oleracea species – cabbage, broccoli, cauliflower, kohlrabi, kale, collards. So when you grow biennials, you must consider how well they do vegetatively in the first year, because you want it to be a good quality cabbage or a good quality beet, carrot. And then you think about how well it stores over winters in your climate. Many of you here in California can just leave these crops out in the field during the winter and they will flower successfully the next year, and won’t get frozen out. But we often do selection in carrots for how well they store, because where I live we often have to store our carrot roots for four and a half or five months.
Then it’s important to look at how well they do as a flowering crop the next year. A lot of people abandon looking at plants for how much vigor health and general overall health during the flowering stages. They don’t think about that.
Then, in some of the OSA seed guides that are coming out you’ll see we describe the optimum over wintering size. That would take a whole class just to talk about. You don’t want a carrot that’s too big or too small to go through winter. There are optimum sizes for all of these crops.
MATTHEW DILLON: Experiment. That’s how we got here in the first place. You as the seed saver experiment with what works in your garden, on your farm, in your system, and through all of this information, if it’s sometimes getting a little technical, just keep that in mind. The only mistake you can make is not trying at all.
SARAH McCAMANT: Yeah, though I made some pretty bad mistakes.
JOHN NAVAZIO: I bet I’ve made more mistakes than you have.
SARAH McCAMANT: It’s just sad when you lose something that you really liked by a bad mistake.
JOHN NAVAZIO: But then you learn your lesson even better.
SARAH McCAMANT: Right. Like putting some wet seed in and it all rotted. We put this as number 2, because one of the things that I discovered that was really different being a seed saver than a gardener was that I needed to be able to pass information along and track it all the way through. This means that your labels can’t fade, you actually need to remember what you planted. When you save it, you need to make sure the bags are labeled. You need to track and record, and the more information the better. So you’re tracking information like health and vigor of the plants, when are they mature, how long does it take for them to germinate. The more information you track, the better seed saver you’ll be, and the more information you can pass on as you share the seed with other people. Just labeling and tracking information is such a different thing when you go from gardener to seed saver, and really getting systems to record that information that isn’t out in the garden. Let me tell you how many labels fade, maps, little notebooks where you write descriptions — make sure they’re out of the garden. It’s something you keep track of through the whole process, because you lose labels every step of the way if you aren’t careful.
We have some envelopes and labels here for seed projects, and you can see we recommend: common names, Latin names, did you keep it isolated, did you select for vigor, a good description of the plant, what year – that’s really important – when was the seed saved? Because if you start seed saving and you don’t write the year, then all of a sudden you have three jars of kale and you’re like, “I don’t know which one is the freshest.” All of that information is very key, so save information, not just seed.
MATTHEW DILLON: You’re not just saving information about the technical aspects, the dates to maturity and everything Sarah mentioned, but it’s also important as a seed saver to save the story of where you got the seed. Even if you don’t know much, even “I just got this from my friend Bill and he didn’t tell me much information but it’s Bill’s favorite bean, and this is what I do know”. And you start to pass that down generation to generation as well.
We don’t always have the exact story. In fact, we rarely have the exact story about any of the heirlooms we pass on. There are many different iterations of seed stories out there for each variety, but I think it’s important to keep that weave alive, keep that heritage alive and to strengthen it each generation by collecting our own stories.
SARAH McCAMANT: When we hold the story, we feel more responsibility to carry it on. I worked on a farm years ago in Santa Cruz owned by Mary Sagorini[ph], a 95-year-old Italian woman, and took care of her orchard. She gave me some bean seed, and I just called it Mary Sagorini’s bean seed. All of a sudden you feel that responsibility. It’s not Blue Lake 724 or whatever. There’s a name and a person, and the more you create what we call seed culture, seed connections, the more likely you are actually going to care for that. We need to bring it back and make it have meaning in our lives.
So the third one is watch for is cross-pollination, which is when we start getting more technical. This is the place that separates beginning seed savers from more advanced seed savers. We always tell everyone to start with the easy ones we call self-pollinators – lettuce, beans, peas, tomatoes – because you don’t have to worry that much about cross pollination with those.
When you move into the more difficult ones, what makes it more difficult is that you have to be aware of pollination and make sure that you’re not getting two varieties crossing and ending up with something different. You have to understand how things pollinate and what they pollinate with. That’s where it gets much more technical and you need books if you’re not already a biologist or scientist who’s been working with this, and where it can give you a little information.
We created this chart, because it talks about how they pollinate. There are different types, self-pollinated, wind pollinated, insect pollinated. And I’m going to let John take it from here on that.
JOHN NAVAZIO: In selfers, “self” means self-pollinated, versus wind or insects, which are always cross-pollination mechanisms.
Self-pollinated systems essentially have a mechanism to cause selfing most of the time, not always. This is biology, folks. There are always exceptions, always a chance of crossing. That’s an evolutionary mechanism built into them to cross a small amount of the time, to mix up the genetics, and to basically incorporate the best genes from other members of that population. So remember that. It’s not 100% all the time.
They always have perfect flowers, which just means both male and female sexual parts. And the pollination and fertilization occurs in two different mechanisms. The first is – if you want the $5 word – is cleistogamous, petals that remain closed throughout the entire flowering process. Essentially, they are restricting insect pollination in that way, even though they’re showy flowers.
How does that work? Some of the Fabaceae, also called legumes, are very showy, but they remained closed. Well actually they’re still attracting insects that are crossing them at a small rate in any given generation.
And then there are other examples. There are self-pollinated plants in the Asteraceae – lettuce and chicories are the most notable – and even though they have open flowers, the pollination and subsequent fertilization that creates the seed happens before the flower opens. So even though blue-flowered chicories are beautiful and open fairly early in the day, that pollination has happened long before they opened, sometimes the day before, and that’s why they can still be selfers.
In cross-pollinated systems there’s always some kind of biological mechanism to assist in crossing. Showy flowers and wind are important – showy flowers, insects; wind for wind pollinated. You’ll have basically separation of male and female sexual parts in different flowers, which means like in squash, you have separate male and female flowers. Easy. You also in some cases have separate male and female plants like in spinach.
Self-incompatibility, just remember, it exists. There are certain crops that just will not receive their own pollen, even though they have perfect flowers. Dichogamy, a temporal separation of sexual parts, and you’ll actually have, like in carrots, where the female part of the flower is fertile before the male, before the anthers shed their pollen. So then the bees and the hover flies and the wasps that are crawling all over your carrots are easily crossing, because on any one flower they’re landing on, there’ll be this separation where they’re not pollinating and recognize pollen at exactly the same moment.
All you need to know is: Is it a crosser? And do I have to worry about cross pollination? How much separation?
SARAH McCAMANT: Let’s talk a little bit more about what you can do if you want to grow plants that are cross pollinators. One is that you can just grow one variety and then make sure, for all the gardeners, that you are watching what your neighbors are growing, because a lot of these can cross pollinate up to a mile. The wind-pollinated crops they recommend a mile isolation from other varieties going to seed.
Some of it you can do by hand pollination. So you can grow squash and actually take control of when and how they pollinate, and you cover the flowers so nothing else can pollinate. Those are techniques that a lot of books describe.
Sometimes you can separate them by time. You can do two varieties of sometimes that would normally cross, but you plant one a little earlier, or two corns, where maybe one’s a 90-day and one’s a 110-day, and so they’re actually going to drop their pollen at different times.
So there are different ways you can control pollination, and deal with cross pollination or not. The simplest one is to just grow one variety and figure out who else around you is growing and make sure they’re not growing something that’s going to cross. That’s the main way I’ve always done it in my garden. But it is tricky, because there are pretty large distances you have to control, and that’s what makes home gardeners get a little overwhelmed with this. “Well I don’t know what everyone else is growing around me.” And then you have to look at other ways of controlling it.
If you go to Seed Savers Exchange, they grow hundreds and hundreds of varieties of things on their farm. They have cages that they build to keep insects out, and they control the pollination, like putting insects in. So there are different ways. The book Seed to Seed actually has some really good techniques for that.
If you start with the easy ones, you don’t have to worry about that. It’s a really good entry point. I call them the entry drugs. You get hooked on it, and then you decide you’re willing to do the harder stuff because it’s so much fun. I think the best entry drug of all seed saving is beans. Some people say tomatoes, because there’s such tomato love in this culture, and heirloom tomatoes are so amazing. This is kind of fun. But beans are even easier, and beans are so beautiful. You grow them and you have these little brown shells that look kind of ugly out there in the fall garden. You gather them all and bring them in, and you start breaking them open, and they’re so beautiful. You can run your hands through them and then you’re hooked.
You do have to worry a little bit about pollination with beans. I just got my first bean cross this year. They do recommend separating two different beans by 10 to 15 feet at least, because you do get some crossing every once in a while.
JOHN NAVAZIO: It can be as much as 4% in some places. The ancestral homeland of beans in North and South America, crossing can be up to 10 – 12%, because the insects that co-evolved with beans are there in their ancestral homeland.
Also, as you get deeper into seed saving, learn more about the history of your crop: What kind of climate it came from, conditions. It will be a real insight into that crop and how its reproductive mechanisms work.
Even if you look at the minimum separation distances, it’s always nice to have a physical barrier between. If you want to do three or four beans because you get totally hooked on beans, then you can grow rows of corn between your beans, or three rows of corn between two bean varieties, or a row of sunflowers, things like that. That will really cut down on that outcrossing.
SARAH McCAMANT: Right. And people say, “Well what’s wrong if I got a little crossing?” There isn’t anything wrong, and actually it can lead you to be a plant breeder when you start seeing some interesting crossing. When most people save seed and grow it the next year, they want it to grow true to type. But if you want to play with it, there’s no reason not to, though it’s good to save some of the seed as true to type so you’re keeping one clean variety.
The next thing I find the most problematic for small growers and gardeners is this: Consider that numbers really count in plant populations. What we’re talking about is there are certain population sizes that are recommended for really getting good quality seed. It goes back to the pollination issue, which is that plants that cross-pollinate. Why do they cross-pollinate? It’s actually a mechanism to increase vigor and overall health of the plant by getting pollen from other plants, and it increases and develops stronger plants. So when you save seeds from small populations, you’re kind of bottlenecking the genes, and narrowing the diversity and the strength of that plant.
On our chart is something called population size, number of plants, and what is recommended. We actually looked for lower numbers in some places based on experience and looking at all the books and guessing. So some of the numbers are going to be different than what John would recommend to farmers. They may be lower, based on, for example, you really can grow arugula with smaller plants than 100, but the books probably say 100. You say, “What the minimum for corn? 100 plants?” Well, they actually recommend 200 plants. We put 100 just so we would get you to do it. Or broccoli, what do we have in broccoli? It’s 40, which is also a smaller number. But that’s kind of intimidating to most home gardeners.
And so that’s where I say do it in a community scale. That’s what we did up in Sebastopol, is we realized that for the numbers it would be hard for most home gardeners to do. We set up a seed garden. All the seed that we grow there goes into our community seed bank. We grow large quantities there. We do our corn there. Every year we do one type of corn, we do 200 plants. It’s something most of us couldn’t do in our own homes, and we’re able to do those kind of population sizes that are good for increased vigor.
If you get those lower population sizes, what you get with a lot of plants is something called in-breeding depression, which means that you’re just getting too narrow of parents. You’re breeding too much your cousin.
JOHN NAVAZIO: You’re marrying your cousin.
SARAH McCAMANT: Right. You’re marrying your cousin. That’s exactly what it is. So you’re always trying to keep the family ties a little broader. You want to marry the people across the street.
MATTHEW DILLON: When you have in-breeding depression, you can save seed from 10 kale plants, and if you plant those seeds, you might not see anything at all in the next generation. So you’re like, “What are these guys talking about, 100 plants? I saved seed off 10 kale plants and everything’s fine.” If you continue to save seed off of 10 kale plants, generation after generation, you will start to see initially problems with reproductive vigor. You’ll start to see mutations in flowers, it’ll start producing less seed, you’ll have more difficulties with just getting flowers to set in different types of crops. Reproduction’s usually one of the first places that you notice in-breeding depression, which kind of makes sense. The plant’s saying, “I don’t want to keep breeding like this; it’s not working for me.” It’s the plants trying to find the solution to a bad situation.
JOHN NAVAZIO: Yes, it is. And as Sarah said, it’s like my sister or my cousin doesn’t look that cute anymore. There is a continuum in all of this. Nothing is etched in granite, folks, when it comes to biological systems. There’s flux and flow in it. There’s no definitive number. If you see 40 on that sheet and you get 38, it’s okay. 42 is better. But what we’re trying to do here is show you there’s a biological continuum.
The wind-pollinated crops need a further distance. And we often say up to two miles with corn because, especially now with the GM corn, we want to make sure people don’t get GM genes in. But Chenopodiaceae or Amaranthaceae on this chart, beets, spinach, they have wind pollen that will travel several miles under certain conditions.
The other thing is when you’re isolating plants, do you ever have 100% assured isolation, where there’s not going to be any crossing? No. And this is the other thing the books lead you to believe. Oh, one mile, it’s absolutely pure, no crossing’s going to occur. It doesn’t exist. The only place you’re going to get perfect isolation is if you go to the moon and grow it on the moon in some module or something.
These are biological systems. There’s always the minimum isolation distance. You can see it grows over time. Peppers cross at a much higher rate than peas do, so we’ve moved them along the criteria. That also means that you need a higher number. The more they cross naturally, the higher number of plants you need. Why? Because of everything that Sarah very nicely just described. They’re yearning for that variation for maintaining the variation that’s in a natural population. Whereas once peas were inbred a long time ago, probably a lot of the peas died out and some of them survived.
SARAH McCAMANT: So the last two tips on this sheet: One is choose ideal plants for ideal seed. This is something that everyone has to realize as they get into seed saving, is that you actually become a plant breeder whether you want to or not. What you save seed from means that you are either saving qualities you like or qualities that you don’t like. It’s called selection. You look for plants that have the best qualities, and that are healthy. The number one thing is you don’t ever really want to save seed from plants that are unhealthy. There are some diseases that can pass from seed to seed. We don’t want to get into the specifics of those, but you can make sure you’re not doing that by never saving seed from unhealthy plants.
The other reason is, if you save seed from unhealthy plants, it means you’re saving seed from plants that are more likely to get sick, so you’re selecting for disease instead of selecting for health. That’s the thing you have to remember is every step of the way you’re selecting for some type, so you want to select for health.
We do a lot of lettuce in our seed garden, and we’re always selecting for slow to bolt. So don’t save seed from the lettuce that bolts first. “Oops, oh I guess I won’t eat that, I’ll save seed from that.” Well then you’re selecting for plants that bolt, and that’s probably the biggest thing with lettuce is you don’t want plants to go right to seed the minute it gets hot.
Te last is about saving the seed once it’s dry. Every seed you have to process differently. We’re not going to get into that. But when you have the final seed, you want to make sure it’s fully dry, and then you want to store in what’s cool, dark, and dry. There’s little ways you can tell whether it’s dry enough or cool enough.
I say glass jars are the number one way to keep moisture out. There are other ways, but it’s really better to have an even temperature than temperatures that go up and down. It would be better to have it at 65 continually than for it to be 32 and then go up to 90 and then back to 32.
Dark/light, you’re going to lessen the lifetime of that seed if it’s out in the light, both getting moist and dry, if it’s changing humidity and it’s changing temperatures.
MATTHEW DILLON: There’s a lot of variation in how long seeds last. Generally, it depends upon the oil content of the seed to some degree, but with crops like parsnips, the seed doesn’t last very long. If you can get your parsnip seed to last three or four years, you’re doing really well. Sometimes it only lasts a year or two. Whereas other crops like beans or corn, you can certainly get your seed to last for 10, 12 years. I’ve had tomato seed that’s lasted for over 10 years, easily. So it depends. Don’t feel bad if you grow a crop and the seed viability and germination drops immediately after three years. It happens.
It can also be not just the way you stored it, but it could be something that happened during the actual growth and maturation and development of the seed, something you didn’t see or you couldn’t control.