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Wakehurst Place, a 500-acre woodland and plant conservation garden in West Sussex, England, hosts one of the world’s largest seed banks. Within the vaults of the seed bank, referred to as Kew’s Millennium Seed Bank Partnership, lies one billion-plus seed from more than 130 countries across the globe.
As a gardener, you may consider cutting down on your seed purchasing costs or the sheer joy of staying connected with nature as motivations for seed saving. But the reality is that the motivations for huge, seed-saving establishments are not that different from yours. You will perhaps appreciate some more reasons by the end of this article.
Seed saving is an important part of gardening, no matter the scale. Therefore, as a gardener, seed-saving techniques should also be part of your repertoire of skills, including saving heirloom seeds, saving flowers, and even preserving seeds for planting in the following seasons.
- What is Seed Saving?
- Why Seed Saving is Important?
- How to Collect Seeds?
- How to Store Saved Seeds?
- Drying Out Seeds
- Should You Store Seeds in The Refrigerator/Freezer?
- How Long Can You Store Seeds?
- Vegetable Longevity Chart
- Annual Vegetables
- Biennial Vegetables
- Is Isolation Distance Important in Seed Saving?
- Controlling Unwanted Cross-Pollination
What is Seed Saving?
All living things generally have an innate, self-perpetuating capacity to ensure their continued existence. For plants, the process revolves around seed production and pollination. Seeds are the products of pollination between plants.
Seed saving is the collection, preservation, storage, and everything in between, ensuring you will have a continuous harvest of the same variety of plants. Each plant you grow will diligently supply you with seeds for the upcoming seasons, a natural cycle ensuring consistent food or flower crops.
Why Seed Saving is Important?
One of the most obvious motivations for seed saving is the potential economic benefits. Let’s face it; seed saving can save you a great deal of money over the long run. A few plants can produce a year’s worth of seedlings.
For instance, if you had a pepper garden, you’d need to cut through a few of them, take out the seeds, dry them, and place them in a sealed container. Only a few peppers would be enough to provide bountiful harvests in the subsequent seasons.
But is learning how to save seeds worth the time and effort? Other than considerably slashing your annual seed budget, more reasons make saving your seeds immensely rewarding. They include:
- Hearty Harvests
- To Preserve Heirloom Seeds
Gardeners from previous generations were dedicated to seed savings. They played a crucial role in developing crop varieties better suited for their local conditions: soil and climate. Therefore, you’d have the peace of mind that the resulting crops would flourish and yield hearty harvests when you used the same seeds.
Over time, seed saving ensures that your crops will become true locals. Crop varieties evolve and become better suited to flourishing under specific, local growing conditions. They will become ‘natives,’ so to speak, well adapted to your patch of ground and almost guarantee successful harvests year after year.
Self-pollinating crops ensure a long line of healthy offspring is preserved if you use the same seeds. Your plants transfer all the genetic information to each other and, therefore, ensure a consistent, healthy yield of the same crops. Self-pollinated plants include crops such as French beans, peppers, chilies, runner beans, lettuce, peas, and tomatoes.
To Preserve Heirloom Seeds
Suppose you paid any attention when learning about biodiversity in high school. In that case, you’d understand that it’s incredibly difficult to perpetuate some of the Hybrid, F1, and GMO seeds that currently fill the shelves of many garden stores. They are mostly sterile, so you can’t quite develop more varieties. And they are patented, too, so you can keep paying for them every season.
Only open-pollinated crops grow more vigorously, provide more diversity, and are more flavourful. With financial and other interests whittling down biodiversity, there’s a real danger of crop varieties disappearing altogether. Therefore, seed saving and storage are the only ways to preserve some of the heirloom seed varieties you currently have.
How to Collect Seeds?
Of course, there isn’t one universal way how to collect seeds. Different crops will have different times or circumstances in which you should collect seeds. Some plants, such as pole beans, have a simple process, which is as easy as waiting for the pods to dry up and then cracking them to release the seeds.
Some crops, such as cucumbers and tomatoes, produce watery fruits and necessitate a different method of organic seed collection. Take tomatoes, for instance, which will produce seeds with plenty of pulp. You’d need to remove the flesh attached to the seeds and wash them thoroughly before drying.
Here’s a simple procedure on how to save your tomato seeds.
- Look for a healthy, ripe tomato from one of your plants. An over-ripe tomato is better since the seeds will have had time to grow to full maturity. Once you’ve identified a plant for collecting seeds, mark it out. Let the tomatoes stay longer, for one or two extra weeks, so that they can be extra-ripe
- Pick one tomato and split it into two to reveal the seeds and the pulp. Scoop out all the seeds and the pulp into a pot or bowl. Add a few tablespoonfuls of water and mush it up a little bit.
- Set the mixture in a warm place and leave it for around four to five days to ferment and break down the pulp and the gel that covers the seeds. Don’t panic if you see some mold on the mixture. It’s perfectly normal.
- Use a metal sieve to skim off the sticky mixture from the seeds and then rinse them with water.
- Air the seeds out to dry on a glass surface or a plate, separating them so they don’t stick together. They’ll stick on paper or any such surfaces.
- They’ll be completely dry in a few days and ready for storage. Toss them into a paper envelope or an airtight plastic container for storage.
The idea, therefore, is to ensure you are saving matured, ripe seeds from healthy crops that are already doing well. Diseased plants will almost definitely pass down undesired qualities to subsequent harvests or never survive till the next harvest. You can also forget about saving seeds from some of the modern hybrid varieties. Their seeds are unlikely to be a genetic match for their parent crops.
How to Store Saved Seeds?
As far as seed-saving techniques are concerned, all the steps are equally critical. Seed storage is as important as seed collection. It would be quite disappointing to collect seeds for you to lose them because of poor storage.
So, what is the best way to store seeds? Of course, different seeds will call for different storage techniques. However, some general tips apply to a range of seed types.
After extracting the seeds, you intend to save, the next step is usually subjecting them to a thorough cleaning process before storing them. This is particularly crucial for seeds that come from a thick pulp. Cleaning up helps eliminate every trace of soil, any remaining debris, and any pathogens waiting to sneak up on your next strain of crops.
Seeds from dry crops are much easier to prepare for storage and may be as easy as shaking them a few times on a sieve to separate them from the chaff. If you have the skill and patience, you could also try to winnow your dried seeds. Simply blow across the seeds as you pour them from one (raised) container to another one on the ground.
Drying Out Seeds
In drier climates, you can leave the fruits on the plants to desiccate themselves. But in damp climates, you may have to pluck the pods, seed heads, or fruits and find a dry spot to place them. You can then extract the seeds when they are dry enough, usually when they make a rattling noise whenever you shake them.
Fruits such as oranges, apples, or lemons are probably some of the easiest plants for seed collection and storage. They hardly require any delicate or intricate care and handling. Their pea-sized seeds are large enough, so you will hardly have to deal with them sticking together.
Simply toss the seeds into a clean, dry, and open container and leave them until they dry and begin to look a bit wrinkled. Seal the container and stash it away until the next planting season or when you go to your next seed trade event.
Vegetables such as cucumbers have seeds typically larger than herbs, making them easier to save. You expose the seeds, which are generally easier to collect as soon as you cut into them. The next step is extracting them and then drying them before saving them.
For other vegetables like pepper, it may be as easy as running your fingers along the length of the seeded walls and letting the seeds drop into a dry and clean container. You can seal the container after a few days.
Should You Store Seeds in The Refrigerator/Freezer?
There’s a lot of confusion about whether or not you should refrigerate organic seeds. While seed storage banks effectively freeze their seeds, freezing your seeds is mostly a risky proposition. Moisture will generally condense more rapidly in a cooler environment.
Therefore, if you are going to freeze your seeds, you’ll require fully sealed containers to keep all the moisture away from the seeds. You may also need moisture-absorbing packets within the containers to keep out every bit of humidity.
Large or commercial seed-saving banks often flash-freeze their seeds. That means their seeds freeze in a much shorter time than it would take, say, a home refrigerator or freezer. Their freezers have huge backup generators, ready to check in immediately when there’s a loss of power, maintaining steady temperatures for the entire year.
There’s also minimal opening and closing of the freezers, and therefore, less risk of fluctuating temperatures. Good luck with replicating these conditions back at home.
Brown envelopes provide great seed storage mediums for most dried seeds. Cool, dry, and darker environments with stable temperatures make the best storage conditions for many dried seeds.
To reduce the risk of moisture in your containers, throw in some desiccant, such as dry white rice or a silicone gel packet. A multiple-chambered storage box where the seed types are separated could come in handy if you don’t want to juggle several packets.
How Long Can You Store Seeds?
Naturally, some seeds will last longer than others. One of the best resources or guides for seed storage is a seed longevity chart (see below). Several seed-saving charts are available in many gardening forums and online.
Some provide information for self-pollinating plants, while others provide information for insect-pollinated plants. Others still provide information for both groups within a single chart. Broad categories include:
Vegetable Longevity Chart
|Amaranth||Wind||2 miles||10||A||5 yrs|
|Arugula||Insect||0.5 miles||40||A||5 yrs|
|Common Bean||Self||10 Feet||10||A||4 yrs|
|Lima Bean||Self, Insect||1 mile||20||A||2 yrs|
|Runner Bean||Insect||0.5 miles||20||A||2 yrs|
|Fava Bean||Self, Insect||50 feet||20||A||4 yrs|
|Yard long Bean||Self||20 feet||20||A||5 yrs|
|Beet||Wind||1 mile||30||B||5 yrs|
|Broccoli||Insect||0.5 mile||20||B||5 yrs|
|Brussel Sprouts||Insect||0.5 mile||20||B||5 yrs|
|Cabbage||Insect||0.5 mile||20||B||5 yrs|
|Carrots||Insect||0.5 mile||60||B||3 yrs|
|Cauliflower||Insect||0.5 mile||20||B||5 yrs|
|Celery||Insect||0.5 mile||30||B||7 yrs|
|Swiss Chard||Wind||1 mile||30||B||5 yrs|
|Collards||Insect||0.5 mile||20||B||5 yrs|
|Sweetcorn||Wind||1 mile||150||A||6 yrs|
|Pop Corn||Wind||1 mile||150||A||6 yrs|
|Flour Corn||Wind||1 mile||150||A||6 yrs|
|Cucumber||Insect||0.5 mile||10||A||8 yrs|
|Eggplant||Self, Insect||50 feet||10||A||6 yrs|
|European Kale||Insect||0.5 mile||10||B||5 yrs|
|Siberian Kale||Insect||1 mile||20||B||5 yrs|
|Kohlrabi||Insect||0.5 mile||20||B||5 yrs|
|Leek||Insect||1 mile||20||B||2 yrs|
|Lettuce||Self||25 feet||10||A||3 yrs|
|Melon||Insect||0.5 mile||10||A||6 yrs|
|Mustard Greens||Insect||0.5 mile||20||B||5 yrs|
|Okra||Self, Insect||800 feet||20||A||4 yrs|
|Onion||Insect||1 mile||50||B||2 yrs|
|Parsnip||Insect||1 mile||20||B||1 yrs|
|Pea||Self||20 feet||20||A||5 yrs|
|Peppers||Self, Insect||500 feet||10||A||3 yrs|
|Pumpkin||Insect||0.5 mile||10||A||7 yrs|
|Radicchio||Insect||0.5 mile||20||B||4 yrs|
|Raddish||Insect||0.5 mile||30||A||5 yrs|
|Rutabaga||Insect||0.5 mile||20||B||5 yrs|
|Spinach||Wind||2 mile||6||A||4 yrs|
|Squash||Insect||0.5 mile||10||A||7 yrs|
|Tomato||Self, Insect||15 feet||10||A||5 yrs|
|Turnip||Self||0.5 mile||25||B||5 yrs|
|Watermelon||Insect||0.5 mile||10||A||6 yrs|
A good number of annual vegetables tend to have longer seed longevity lives. Cucumber seeds, for instance, can last up to eight years for both male and female flowers. Melon, insect-pollinated, can produce seeds that last up to seven years. Other annual vegetables with relatively long seed life include;
- Pumpkin: insect-pollinated, seven-year seed life (both male and female flowers)
- Eggplants: self-pollinated, six-year seed life. For best results, harvest seeds from the most over-ripe fruits.
- Watermelon: insect-pollinated and doesn’t cross with other melon types, six-year seed life
- Corn: the seeds mature in 6-8 weeks after the consumption stage and will last for six years
- Tomato: self-pollinated, six-year seed life
Mostly wind and insect-pollinated, biennial vegetable varieties tend to have shorter seed storage lifespans. Some of them have an extremely short seed life that hardly goes beyond a year.
For instance, Parsnip, insect-pollinated, will produce seeds that last for a maximum of one year. Onion and leek, both insect-pollinated, won’t be useful beyond two years, and carrot seeds will last for three years.
Therefore, a seed longevity chart is a helpful resource for saving organic seeds, especially since seeds have varying storage durations. Of course, seed longevity also depends on several other factors, such as the conditions in which it was stored and the conditions under which the particular crop grew.
As a result, the seed longevity numbers you will encounter in most charts are averages and not solid guarantees that they will last that long.
Note: The above figures represent optimal garden-scale seed saving and storage numbers. If you want to see the principles in practice, watch the video below, where I take you through how it works in the garden.
Is Isolation Distance Important in Seed Saving?
One key metric worth noting when it comes to seed saving, and by extension, seed storage, is the isolation distance of the plants. Seeds from self-pollinated vegetables and plants are generally easier to save. They provide a better chance of passing down a plant’s unique, healthy traits. But cross-pollination can complicate seed saving by essentially interfering with a strain of crop varieties.
Cross-pollination isn’t entirely bad, but it would be undesirable if you are keen on maintaining particular traits of different varieties of the same species. Suppose you are growing a strain of important food crops, flowers, or ancient heirloom varieties. In that case, cross-pollination might be more of a threat, especially if you have varieties of the same species nearby.
And the other plants don’t even have to be within your garden. Your neighbor’s plants might cross-pollinate with your plants if they belong to the same species. But don’t get too paranoid. You can limit self-pollination.
Controlling Unwanted Cross-Pollination
So how do you control unwanted cross-pollination (without losing your head)? You isolate the plants when you grow them. There are three main methods; timing of the flowering, containment, and distance.
Distance is the most accurate isolation method and presents the best chance of controlling unwanted cross-pollination. Different plants require different isolation distances to prevent or limit the chances of cross-pollination.
Without getting into the biology behind the recommended distances, the isolation distance depends on the ‘mating system’ of a crop variety or the different species within the variety. As a rule of thumb, self-pollinating flowers will require shorter isolation distances. Cross-pollinating ones, on the other hand, will need longer distances.
Other factors also influence the chances of cross-pollination. They include wind directions, physical hindrances, landscape, the local population of pollinating insects, and their travel patterns. So, getting a seed-saving chart from a reputable source will save you the headache of considering all these considerations before determining the proper isolation distance for your crops.
There are at least 1000 known seed banks, collaborations, and exchanges worldwide. This only emphasizes the art and practice of seed saving as one of the most important parts of gardening and farming in general.
We’ve only scratched the surface regarding seed saving and why it’s important to start saving your seeds if you are not doing it already. There’s a lot more information about seed saving than can be packed into a single article.
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Remember, folks, You Reap What You Sow!