Seeds hold within them the promise of new life. Given special care, seeds can remain viable for much longer than if they are exposed to environmental conditions. Low germination rates may be indicative of decreased plant vigor. In this post, we will discuss basic seed storage techniques to get the longest possible viable storage life.
Ideal Conditions for Seed Storage
Seeds are alive, albeit in a dormant state. They continue to carry on with basic life processes just at a markedly reduced rate. Seeds will continue to exchange elements and gases with the atmosphere while they are in a dormant state.
We want to protect that tiny embryo from anything that might speed up its metabolism and cause it to use up its stored food during storage. The key is to keep seeds in that dormant state while in storage by protecting them from moisture and warmth.
Seeds Must Be Protected from Moisture
Seeds will absorb moisture from the air. When that moisture combines with stored nourishment inside of the seed, it will form a soluble food and combine with oxygen. This will result in the release of water, carbon dioxide, and heat. The production of heat will impact the seed’s ability to germinate.
Store Seeds in a Cool Environment
Storage temperature significantly affects the viable shelf-life of seeds. The cooler the temperature, the longer the viable storage life of seeds. Mold and insects increase in warmer storage conditions.
James Harrington Ph.D. conducted studies related to seed longevity and storage temperature. He concludes that for every decrease of 10°F (5°C) in storage temperature the life of the seed doubles. This rule applies to temperatures between 32°F to 122°F (0°C to 50°C).
Microorganisms can damage seeds. Fungi and molds thrive in temperatures between 85°F to 95°F when moisture levels in the seeds are between 13 and 16 percent. When storage temperatures drop to 50°F fungi and molds are almost non-existent.
Will freezing seeds extend the shelf life?
Freezing is a great way to extend the storage life of seeds. It becomes critically important that you store the seeds inside of a moisture-proof container, so you do not introduce moisture into the seeds and ruin them. Allow the seeds to gradually warm to room temperature for 24 hours before planting them. Refrigeration is also a great option for storing seeds.
Seed Storage Pest Control
Seed packaging must protect the seeds from critters and insects that may want to enjoy them as a quick meal. Infestation can quickly destroy your seed vault if you don’t protect it in an appropriate container. Make sure that the packaging is rodent-proof. Oxygen absorbers will easily control insects and may extend the shelf-life of stored seeds. Freezing can also control insects during storage.
Storage Gases Impact Seed Storage Life
Studies show that a nitrogen or carbon dioxide atmosphere will increase the storage life of seeds. The use of an oxygen absorber in a sealed container such as Mylar or a glass jar will not harm the seeds and may help to extend the shelf life because it leaves all of the nitrogen behind.
Vacuum sealing has been shown to extend the storage life of larger, sturdy seeds such as beans, peas, and corn. However, use caution with more fragile seeds where vacuum sealing may cause physical damage to the seeds, preventing germination.
Select Quality Seeds for Long-Term Storage
Only the best seeds should be considered for long-term storage. The seeds should be mature, normal color, without injury or defect, free from fungi or microorganisms, and no insects or eggs should be present.
Safe Moisture Limits for Long-Term Storage Seeds
Not all seeds have the same moisture content. James Harrington Ph.D. is known for his research on seed storage. His research shows that for every 1 percent decrease in seed moisture content between 5 and 14 percent, the life of the seed doubles. Seeds should not be dried below 5 percent moisture. Above that level, studies indicate that drier seeds will result in a longer viable storage life.
|Seed Moisture Content||Viable Storage Life|
|8-10 percent||4 years|
|9-11 percent||2 years|
|10-12 percent||1 year|
|11-13 percent||.5 year|
Microorganisms will damage seeds. Bacteria need a moisture content of 18 percent to damage seeds. Fungi and molds can cause damage when the moisture level is between 13 and 16 percent in warm temperatures.
How to Store Seeds for the Longest Viable Life
Storage conditions make all the difference in the viable storage life of seeds. Seeds should be stored in an air-tight container, in a cool, dry, dark location.
You may be interested in a little experiment we conducted using our own stored wheat to see if it would sprout. The samples varied widely. The containers included #10 cans and plastic buckets. Some were stored with oxygen absorbers and some without. You might be surprised at the results. Super Survival Sprouts: Powerful Nutrition From Your Stored Wheat
We also conducted a similar study sprouting old, stored beans. We sprouted beans that were stored in a wide variety of containers. Some beans were fresh but one of the cans of beans were 29 years old. Food Storage Experiment: Will Old Beans Germinate
We learned that storage conditions do make a difference but that some of the beans remained viable for a very long time.
How do storage conditions impact the germination rate of seeds?
The germination rate declines as seeds age. The ideal storage conditions of cool, dry, and dark slow down the deterioration of the seeds enabling them to remain viable for a longer period. It also protects them from the growth of microorganisms that can damage them.
Plant viability is also impacted as germination rates fall. In our experiment sprouting stored wheat, we had some seeds that germinated but then they just wouldn’t continue and make a healthy plant. Poor things were completely exhausted just from germinating and did not have the strength to go on.
How long will can I expect stored seeds to be viable?
Seeds do not expire. The germination rates and viability just gradually decrease. The better the storage conditions as discussed above, the longer the seeds will maintain their original quality. The expected viable storage life is impacted by the original quality and moisture content of the seeds, the storage temperature, and the protection from moisture the seeds received in storage.
Varieties of seeds have different shelf lives. Onions have a short shelf life of only a year or two while greens can easily last for 6 years. Generally, seeds that are stored under ideal conditions may maintain acceptable levels of germination for between 3 and 14 years, depending on the variety of seeds.
Estimated Viable Storage Life for Garden Vegetable Seeds
The table below includes the typical range for seeds that have been stored under the ideal environmental conditions of cool, dry, dark, and in an air-tight container.
|Seed Type||Average Viable Life|
|Flint Corn||6-12 years|
|Sweet Corn||3-5 years|
|Squash (Summer and Winter)||6-10 years|
What are the best storage containers for storing seeds?
Seeds store best in an airtight container that protects them from moisture, light, and rodents.
Ziplock Plastic Freezer Bags
You can place paper envelopes of seeds inside of a zip lock freezer bag to protect the seeds from moisture. This is a handy way to slip them into the refrigerator or freezer because plastic bags don’t take up much room.
Mylar bags create a true oxygen and moisture barrier as well as protect the seeds inside from light exposure. You can place seed packets inside of a Mylar bag and add an oxygen absorber to remove the oxygen and allow the seeds to live in a high nitrogen atmosphere which should make them very happy as well as prevent any issues with insects.
Mylar bags are subject to rodents. It is a good idea to place the Mylar bags in a secondary container to add a layer of protection. A small sturdy plastic tote will protect from mice but probably not stop a rat.
I seriously love mason jars for just about everything. I like that I can see what is inside without having to open the jar. Glass provides a true moisture barrier, but the seeds will need to be protected from light.
Mason jars aren’t your only option. You could use little baby food jars or repurposed spaghetti sauce jars. I like to store seeds in the original packaging inside of the glass jars. You could drop an oxygen absorber in or vacuum seal if you want a long shelf life.
The possibilities are pretty much endless when it comes to storing seeds in plastic containers. Just make certain that the lid fits snuggly. Plastic bottles are ideal for keeping out moisture which just happens to be one of the biggest enemies of stored seeds.
Vitamin Supplement or Prescription Bottles
I repurpose vitamin supplement or prescription bottles for seed storage. The containers tend to be really durable and small enough for each variety of seeds that I harvest from our garden. I have a friend who stores seeds in those black little film canisters he still has from back when cameras used film.
Plastic Buckets or Totes
I’m a huge fan of Survival Garden Seeds Farmer’s Collection which comes in a little rectangular plastic bucket. It is perfect for organizing the packets of seeds and protecting them from moisture. Use the promo code PROVIDENT for 10 percent off your purchase.
Another great option is small shoebox-size totes. They protect the contents from moisture. I love the way that I can see what is inside of them. They stack nicely so I can organize different varieties in them and quickly access whatever seeds I need.
#10 Can with Plastic Lid
Repurposing #10 cans is another great idea for storing seeds. Save the white plastic lids and you have a free, moisture-proof container to organize all of your seeds in.
Our Future Depends on the Seeds We Store Today
We simply cannot have a harvest if we don’t have seeds to plant for the next year. It is a wise idea to have several years of seeds in your prepper stash. Grow a garden each year so that you can develop the skills, tools, and quality soil that you need to produce your own food. In addition to storing seeds, plant perennial plants that grow back every year like fruit trees, berry bushes, grape vines, and perennial herbs.
I purchase some seeds and save some of my own seeds every year. I still have failures and success with every garden I plant. However, as the years pass, I find my failures to be significantly fewer and my successes most sweet.
Remember, you can only save seeds from heirloom or open-pollinated plants or the next generation may not be true to the parent. One year I saved pumpkin seeds from a pumpkin I had purchased. I saved the seeds and planted them the next year and grew some very lovely, but not edible, gourds.
I strongly recommend purchasing a seed vault from Survival Garden Seeds to get you started. They only offer non-hybrid, non-GMO heirloom seeds. The seed collections are reasonably priced and if you use the promo code PROVIDENT you will get 10 percent off your order. Each seed packet has growing instructions on the back as well as directions to save seeds from the harvest.
- Home Garden Collection with 30 seed varieties
- The Homesteader Collection with 50 seed varieties
- The Farmer’s Seed Vault (my favorite) with 100 different heirloom seed packets.
It’s time to store some seeds … and store them correctly.
Thanks for being part of the solution!Jonathan and Kylene Jones