How to Harvest and Store Seeds
Whether you're a homesteader or amateur gardener, harvesting your own seeds is an excellent way to continue your garden for years to come. With global food supply concerns along with rising costs at the grocery store, creating your own "seed bank" is a way for you to save money and gain control over what you're growing and eating.
Harvesting your own seeds also ensures you are using known varieties that perform well in your particular region. It allows you to continually plant the species you know and love, while stocking up your seed catalog.
These seeds can be shared with other gardeners as gifts, at seed swaps, or donated to local seed libraries. Here's how to harvest and properly store seeds so they can easily be replanted.
Seeds You Should Harvest
The best seeds to save will be "true to type", meaning they are self or open-pollinating and will continue to produce the same plant year after year. Seeds from hybrid or cross-pollinated plants are not recommended as you never know what type of plant will result from their seeds.
Open-pollinated plants can also be old-fashioned or "heirloom" varieties.
Always save seeds from high performing plants. Choose the tastiest, healthiest growers or ones that have attributes you prefer over others. Never save seeds from diseased or poorly performing plants, even if you want to grow that species again.
Certain seeds are easier than others to store, and therefore are recommended for saving. Beans, peas, and peppers have seeds that don't need special attention before they are stored. They also have self-pollinating flowers so you don't have to worry about cross-pollinating species.
Others like beets and carrots are biennial plants, meaning they require two full seasons before they produce any yield. You need crops to get seeds, as this is a part of the plant's full growing cycle.
If you really have your heart set on beets or other biennial crops, then the wait may be worth it for you.
Types of Seeds and Pollination
Open pollinated plants are ones that are visited by bees, butterflies, birds, and other pollinators that help to fertilize the plant.
Wind, rain, and other means can sometimes account for open pollination, as well. These seeds will continue to produce the same plant year after year, especially if they are self pollinators (not all are).
Self pollinating plants have both the female and male parts so that the plant can fertilize itself without the need for another plant, or help from pollinators.
Note that all heirloom plants will be open pollinators, but not all open pollinators will be heirloom. All heirloom seeds are non-GMO with their heritage well-documented from being passed down through generations. This gives them a known status of producing a specific kind of plant for decades, or even centuries.
Hybrids are another way that farmers have successfully produced plants that are known to grow well or have particular characteristics. This is done by cross-pollinating two different plants to create a fully unique one.
Cross pollination can also happen by accident in nature if you plant certain species close to each other, resulting in an unknown and often undesirable plant.
Seeds from hybrids will not produce the same plant again, you have to keep buying these seeds to get the plant you desire. They can be better growers and more disease-resistant than open-pollinated plants, and there are organic, non-GMO hybrid seeds available.
Open pollinated plants may cross pollinate with other plants and produce seeds that grow similar plants to the parent, but not exact replicas. They may still be very good plants.
In general, open pollinated plants will produce either true seeds or ones that are very similar through potential cross pollination.
To know whether any of these options are possible, look at the specific labels and information of each plant.
This will help you decide which plants to pair next to each other to prevent unwanted cross pollination. For instance, certain squashes will cross pollinate with zucchini resulting in a bad combination, so planting them away from each other is recommended.
When to Harvest Seeds
For any plant, you should start collecting their seeds once the plant has finished its growth cycle. With fruits and vegetables, this means after they've produced their yield, or temperatures start to signal their end. When a plant bolts or flowers, it eventually offers its seeds in some way.
Annual and perennial flower seeds are ready to collect once they have finished their bloom stage. Some plants naturally showcase their seeds, whereas others will host them in husks or pods.
Another sign that the seeds are ready to harvest is when petals fall off and the plant starts to dry out.
Fall is usually the best time to collect any seeds from shrubs and trees, though these seeds can be much trickier to prepare for planting. You need to mimic nature's condition, so if a tree seed or acorn needs a hard frost to harden it off over the winter, you would need to mimic this somehow.
Otherwise, keep an eye on your garden from the start of spring until late winter to harvest seeds from plants as they die off with seasonal changes.
Most fruit and vegetables should be left to ripen past their good eating stage, but not let go to rot. Just slightly overripe is perfect for seed collecting.
Flower seeds should be somewhat dry when collected, or an entire flower head can be pruned off and kept in a safe place to fully dry out. This may take longer, and sometimes seeds aren't fully developed this way.
How to Clean and Prepare Seeds
There are many different ways to clean and prepare a seed for storage, but in general, seeds fall into two categories: wet and dry. Wet seeds are what they sound like: they are harvested from inside of the plant, are moist, and surrounded by pulp. They come from plants like tomatoes, eggplants, cucumbers, and squashes.
Wet seeds need to be separated from the pulp, but some will benefit from an extra step of fermentation to remove pathogens and bacteria (especially tomatoes and cucumbers). In this case, seeds should be cleaned after the fermentation process.
To clean them, put wet seeds in a bowl of water and discard any seeds, pulp, and debris that float to the top after a few minutes. Any floating seeds are non-viable. Siphon healthy seeds that have stayed at the bottom through a strainer.
Continue to rinse until no debris is left, and then lay them out to dry on a towel.
Once most of the moisture has been soaked up, move them into a container or a hard, flat surface like a clean plate or baking sheet and keep them in a dry, shaded area for a few days to a week until they completely dry out.
Dry seeds come from herbs, beans, peppers, and flowers, and won't have any wet pulp or moist material to clean off.
Even though they are already dry when harvesting, you still want to let them dry out more. Storing them in a paper sack can be an easy way to let them dry out safely.
Cleaning them involves the sometimes cumbersome task of removing pods and husks, as well as screening or winnowing them so they separate from the chaff, essentially getting the actual seed without any outer casing.
Every seed is a bit different, which is why it's best to research them all individually before cleaning. You'll start to get the hang of this process the more you do it, and cleaning different seeds will become second nature.
How to Store Seeds
Seeds can either be stored in small paper envelopes or tightly sealed containers like mason jars (glass is best). Generally ones in paper envelopes are good for short term (within the year) and glass jars are better for long term storage.
Keep all seeds in a cool, dry, shaded part of the house that won't be exposed to any extreme sunlight or heat.
Silica gel desiccant packages can be added to containers to help absorb any extra moisture. Always label your packets or jars, writing their name and variety as well as the date they were stored or collected.
Write as much info as you want, as memory lapses happen when spring finally comes around!
Seeds should be used within one year for the best results, as older seeds lose some of their viability.
Again, this depends on the species, as some plants like leek and onion seeds will only last a year, but beans, carrots, and peas can last up to three years with proper storage.
Some melons, lettuce, and cucumber varieties may last up to five years.
Fruits and Vegetables
Edible crops produce both wet and dry seeds depending on the plant. Tomatoes, cucumbers, eggplant, melons, and squashes will produce wet seeds which can be harvested once the fruit has ripened passed its eating stage.
Beans, peas, and peppers have dry seeds that can be cut away from the plant or pried out of pods. These generally won't need to be cleaned as much as the wet ones, and will dry out faster.
Some fruits and vegetables have both hybrid and open pollinated varieties. San Marzano or Brandywine tomatoes are open pollinators and will produce identical fruit to their parents, but there are also many hybrid tomato varieties.
Interestingly, certain hybrid tomato plants such as Big Boy, and Early Girl are also known to produce viable seed that takes the best qualities from each parent plant.
While it will be hard to predict exactly how the plant will turn out, gardeners are confident in their seed quality. This is because these hybrids have gone through years of self-selection.
Some open pollinating vegetable plants that are known to produce true to seed are California Wonder peppers, Little Marvel peas, and Kentucky Wonder beans. You won't have to guess what kind of plant their seeds produce, but plants will still need proper conditions to grow well.
Perennials and Annuals
Perennials will produce dry seeds, so remove any husks or pods and place the seeds in a paper sack to dry out before storage. Some of the easiest perennial flowers to collect seeds from include coneflowers, Black-eyed Susans, and Speedwells, especially the 'Veronica' variety.
Keep in mind that some seeds are worth saving more than others. Seeds from a hosta or bee balm may not make as much sense since these perennials are prolific growers and can be divided quicker than you can grow a new plant from seed.
Seeds from annual plants can be harvested similarly to perennials, but keep in mind that different flowers, whether they are perennial or annual, will have different bloom times.
Be prepared to collect seeds at various times of the growing season.
Some annuals that are easy to collect seeds from are marigolds, nasturtiums, poppies, snapdragons, sunflowers, and morning glory. Wildflowers drop their seeds naturally or "self-seed".
Leave blooms on these plants up to the end of the season so that they can work their own magic; or, save some manually if you'd like to plant in another area, or share with others.
Note that "composite" flowers which include sunflowers, daisies, coneflowers, and others that share their open-face characteristics will produce many non-viable seeds as well as healthy ones. Planting extra, or finding out how to differentiate viable from non-viable for each species is recommended before storing.
Harvesting seeds from herbs is another wonderful way to add more spices and flavors to your kitchen, and they are often quite easy to collect. Most herbs will have dry seeds that can simply be added to a paper sack once harvested from the plant.
Herbs are seasonal growers, so when the plant bolts and creates flowers, these flowers will go to seed.
Seeds from plants that grow from bulbs can also be saved, and can speed up the process of propagating more springtime flowers.
Some perennial bulb plants like irises and daylilies grow quickly and can be divided easily, so saving their seeds may not be the best way to get more plants.
Trees, shrubs, and vines create their own kind of seeds, as well. Most tree seeds need to be kept in a very cold place, and some shrub seeds will need to be removed from their surrounding casing or berry.
Trees can produce nuts, acorns, berries, winged seed, and cones so harvesting and storing them will be unique to the species.
When first starting out with seed collecting, it can be overwhelming to think of all the various kinds of seeds you could potentially collect and store for later. Keep it simple, and start with a few easy plants like flowers and herbs or a handful of fruits and veggies.
Annuals don't come back and can't be divided, so they are great choices for seed collecting, especially since they produce so many. Fruits and vegetables are also very rewarding since you can continuously grow the same plants that have produced well.
Collecting your own seeds also means that through self-selection, you can create your own specific breeds of plants that won't be found in stores or sold commercially.
If you have a prized flower, rather than going out and purchasing similar seeds, harvesting the ones from the plant itself is the best way to ensure you get more of the exact plant you love so much.
This is why it's important to save seeds from good performing plants that didn't suffer from any disease or produce weak fruit, as you can be confident that they have adapted well to your garden.
Allow for the process of trial and error and have fun along the way. Seeds contain a plant's entire life in them and the cycle is magic! When learning how to harvest and store seeds, leave expectations at bay, and allow for a little bit of this magic to happen naturally.