How to Save Seeds to Maximize Their Shelf Life

Gardening is a great way to save money on your grocery bill and also enjoy beautiful flowers and greenery throughout the year. As rewarding as it is, it’s also a lot of work: year in and year out you’ll be planting, caring for, pruning, and harvesting. The worst is when, through no fault of your own, your plantings fail to germinate.

Troubles with the commercial seed supply have led many gardeners and homesteaders to start collecting and saving their own for future use. Done right, it’s a great way to ensure higher success rates and a more bountiful harvest or blooming season.

Keep reading and I’ll tell you everything you need to know, from choosing a proper container to processing and a lot more.

Using the Right Container is Crucial

First things first: if you want to store them long term, meaning longer than a few weeks or months, you’ve got to pick the right container.

The good news is that virtually any container can work as long as it will protect the seeds, block light from getting to them, and maintain the correct
environment.

Containers don’t necessarily have to be airtight, but often allowing a little bit of airflow is better for longevity. Similarly, clear containers are okay as long as you keep them in a dark environment or otherwise protect them from ambient light.

The following are some of my favorites and ones that have a proven track record:

Small Envelopes: A classic technique that your great-grandma probably used. Keeping seeds inside envelopes makes them easy to store in cabinets, drawers, and other convenient locations. The downside is that they aren’t particularly pest-resistant, and if they get wet in any way, they tend to stay that way.

Coin Envelopes: One of my very favorite methods for seed storage. Coin envelopes are the perfect size for stashing small quantities.

Plastic Bottles: You can use virtually any plastic bottle for keeping seeds. Don’t believe the old complaint about chemicals from the plastic leaching into them, or direct contact with plastic somehow harming them. Lots and lots of people have used plastic for years with no ill effects.

Mason Jars: Another time-honored method, mason jars and other small glass jars are excellent for our storage needs. They are highly pest-resistant, tend to be airtight, are durable, stackable, and reusable. I like keeping baby food jars for the purpose. A major downside is that most are fully transparent, which can make light exposure an issue.

Seed Packets: If you buy seeds from the garden center or outdoor department at your local hardware store, you can simply keep them in the packet they come in.

Plastic Food Storage Bags: Zipper-locking plastic food storage bags are a workable option here. They tend to be vulnerable to condensation and are typically transparent, but other than that, they work well.

Vacuum-Seal Mylar Bags: A great method for long-term storage since the metallic coating on these bags completely prevents the intrusion of air and moisture.

Note: Never reuse any container that held dangerous or questionable chemicals, as these can potentially compromise your seeds. Likewise, all food containers must be thoroughly washed before repurposing to prevent bacterial outbreaks.

Label Seed Containers with Relevant Info

The relevant info: what kind of seeds they are, of course, but also the crop that they came from, the variety, the date that you packed them, and anything else you think might be useful to future you.

How to Save and Store Veggie Seeds, Step-by-Step

The key to long-lasting seeds is in proper cleaning, preparation, drying, and finally storage. These steps will walk you through it:

Step 1: Remove chaff, wash seeds, separating all other plant matter. Pick off fibers, bits of skin, and other stuff. Gently wash off slimy or gunky seeds in room-temperature water.

Swirling them in a bowl of water is usually sufficient and helps prevent loss. Strain through a sieve if you need help collecting them.

Step 2: Spread seeds in a single layer on a cutting board, plate, or other convenient surface that is lined with parchment paper. A large, flat mesh strainer is even better. Prevent them from clumping up and make sure air can move freely between them.

Step 3: Provide airflow bysetting the seeds in a warm place, at least 60°F / 15ºC, to dry. Steady airflow is highly beneficial, so set up a fan that will blow air across them. Take care that it doesn’t blow them away!

Step 4: Rotate seeds once or twice a day going forward, Flip them over, rearrange them; this will promote even drying.

Step 5: Check for dryness and keep rotating the seeds and ensuring airflow until they are completely dried out. Depending on the conditions and the type, this can take a couple of days or up to a week or a little longer.

Step 6: Store seeds once they are completely dried out. Transfer them to your chosen storage container and put them away. Don’t forget to label the container!

Shelf Life of Seeds

As a rule, if you follow all of the steps above, you can expect them to last at least a year in storage, and most will last up to five.

With an extraordinarily good container and kept in the dark and quite cool (40°F / 4ºC or lower but above freezing), it’s possible for some kinds to last upwards of 10 years.

Special Procedures for Certain Veggies

The following are for the most common fruits and veggies:

Corn: High oil content means short life. Most varieties last only a year in storage at most; try to use them within several months.

Pumpkin: Pumpkin seeds are comparatively huge and dense, and take longer to dry out. Give these whoppers at least 7 days, and probably closer to 10, in ideal conditions before storing.

Garlic: Another seed that just doesn’t last that long compared to others. They give you one to two years tops in storage under ideal conditions.

Onion: Another allium genus veggie. Just like garlic, onion seeds will last a maximum of two years stored in ideal conditions. Even then, viability rates will have fallen considerably.

Chives: Same as onions and garlic. Degrades quickly in storage. Use within a year for best results.

Spinach: This nutritional powerhouse unfortunately does not last that long compared to some of the others we talked about above. Plant within one year for best results.

Kale: Kale seeds have a modest shelf life in storage of around 2 years.

Cucumber: Don’t keep cucumber seeds from perfectly ripe cucumbers you pick for eating. They need to stay in the fruit longer, past the point of ripeness, to properly develop prior to cleaning, drying, and storage.

Mark a few particularly healthy plants and leave a couple of fruits behind to fully mature prior to collecting seeds.

Tropical Fruits: Tropical fruit seeds, of all kinds, are notorious for short shelf lives. Don’t expect any of them, including mangoes, pineapples, and bananas, to last more than a year in storage at most.

Saving Flower Seeds

First, you want to leave the blooms on the plants to wither, brown, and dry naturally. This is, again, an important step in the development of the seeds themselves.

When the stem of the bloom is fully brown and dry, snip off the bloom and place it in a bowl or other container. Then break apart the bloom carefully and sort the seeds from the rest of the debris. Note that many flowers have seeds that look radically different, so you’ll have to learn to identify them species by species.