Here are my recommendations on how to keep seeds fresh. Or in other words, the best way to store seeds for better germination.
How to Keep Seeds Fresh Without Doing Them Damage
That’s right, one of the most common ways people store their seeds is to put them in the freezer. Usually, I read this in Facebook threads, ugh.
This is a bad idea because you could damage the seed in several ways.
You can hear my reasons in my podcast episode on how to keep seeds fresh. I will also discuss my reasons below.
Microgreens Podcast Episode 39
Subscribe to the Podcast
Click to visit the Microgreens Podcast on your favorite platform below. Or visit your favorite and subscribe!
Home Microgreens participates in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com. As an Amazon Associate, we earn from qualifying purchases. We may earn a small commission from the companies mentioned in this post at no additional cost to you. Not all links are connected to affiliate companies.
Links to Items Discussed in Episode 39 of the Microgreens Podcast
Airtight Containers
I store my seeds in these Lock & Lock Containers. They are airtight, lock securely, and don’t break if dropped.
FREE Home Microgreens Grow course that teaches you the basics of growing microgreens in your home! There are 12 video lessons (over 120 minutes), downloads, and more written information and tips!
They come in different sizes and groupings. Click to see the Lock & Lock Store.
Silica Gel Packets
I use these silica gel desiccant packets. They remove humidity and moisture from containers and work very well with the Lock & Lock containers to keep the relative humidity low around your seeds.
Support the Microgreens Podcast Show
Supporting the Microgreens Podcast will increase the frequency of episodes.
How I Store My Seeds to Keep Them Fresh
I discuss the best way to keep seeds fresh last.
Cutting to the chase, here is how I store my seeds in the house.
Store Seeds in Airtight Containers
I store them in Lock & Lock Containers. I use many different sizes but remember that you don’t need to dump the seeds out of the packets that came in to store them in the containers.
You can get a larger container and put all your seed packets in one. Add a couple of silica gel packs, and you are all set.
Add Some Silica Gel Desiccant Packs
These desiccant packs will remove moisture from the container and lower the relative humidity in the air inside the container, even in humid environments. They work, you should use them.
Store the Containers in the Dark
I don’t go crazy here, meaning I place the containers in a closet and close the door. I don’t darken or put black paper on the containers. I simply put them in a closet and close the door.
Keep Temperatures as Even as Possible
I do not have a closet on the north side of my house. That is the best place in a home without a basement or another room with cooler temperatures. The north side does not receive any sunlight that will heat up the wall to the closet. A south-side outside wall closet is not a good place to store seeds.
My closet is in the home’s interior and in a room that is kept at the most moderate temperatures—no wide temperature swings.
Cellars Work Well
If you have a cellar (or another room cooler than the rest of the house), this is a good place to store seeds. Don’t worry about the dampness because you put desiccant packs in the containers, right?
Garages Don’t Work Well
Garages are not very good at keeping temperature swings under control. Even if the temperature extremes are not extreme, the temperature may change more rapidly than the desiccant packs can absorb the moisture due to relative humidity changes.
A constant warmer temperature is better than cooler temperatures that fluctuate wildly.
That’s It. I Don’t Refrigerate or Freeze My Seed
So many people tell me they keep their seeds in the refrigerator or freezer.
I don’t think the risk of condensation forming on the seeds or inside the container is worth it.
If the seeds have too much internal moisture content, above 14%, there is a risk of ice forming inside the seed and killing it as the sharp ice crystals expand in the seed germ.
If you buy so many seeds that you need to preserve them by freezing them, you are buying too many at once.
The Number One Way to Keep Seeds Fresh
Don’t buy too many.
It is as simple as that. Yes, they are cheaper if you buy a larger quantity of seed. But only if they do not become damaged before you use them.
Having some reserve is excellent! Too much, well, you never know what will happen to them.
Length of Seed Viability
These data were collected from different sites and combined. If ranges differed greatly, the more conservative values are reported. The assumption is that good seed storage principles are practiced.
Some sites listed outrageous ranges like 1 to 5 years or 2 to 6 years. There were not included in the list below.
These include garden varieties and those used as microgreens.
Note: At some point, I’ll put them in alphabetical order.
Seed Viability & Longevity Chart
One to Two Years
Chives
Garlic
Leek
Onion
Okra
Parsley
Parsnip
Pepper
Shallot
Sweet Corn
Three to Four Years
Asparagus
Beans
Broccoli
Brussels Sprouts
Cabbage
Carrot
Cauliflower
Chinese Cabbage
Kale
Kohlrabi
Spinach
Celery
Chicory
Celeriac
Eggplant
Peas
Pumpkin
Rutabaga
Squash
Swiss Chard
Tomatoes
Turnip
Watermelon
Five to Six Years
Basil
Cucumber
Cantaloupe
Endive
Lettuce
Mustard Greens
Radish