When my husband and I first bought our farm, we were so excited to have more space to grow our own food. We found a sunny spot in our yard, borrowed a tiller from a neighbor, and bought ALL. THE. SEEDS.
Seriously, I don’t know how we thought we would ever plant them all. A small basket of neatly organized seeds quickly turned into two baskets of seed packets randomly thrown together. Add in a couple successful harvests, and we had random brown bags marked with the names of seeds we had saved. It was a hot mess.
And worse of all, we had no system for rotating out old seeds or storing them so they retained their viability.
Within 5 years, most of the seeds had completely stopped germinating. Oh, we tried. We wasted a lot of potting soil in the process. In the end, we threw away two baskets of seeds (and several brown paper bags) and just started over.
Could we have saved those seeds? What could we have done differently to save them?
If 2020 has taught us anything, it’s that seeds are precious. Not that every seed will germinate or grow into a healthy plant, but we should work hard not to squander them. Without seeds, we can’t grow food.
So what are our best ways to ensure seeds stay viable for as long as possible?
Where to store garden seeds
Sun, heat, and moisture (the very things a seed needs to germinate) are the enemies of seed viability. So your first step will be to keep your seeds in a location that is cool, low humidity, away from direct sunlight, and with minimal temperature fluctuations. This means you shouldn’t store them in the shed or garage.
How many times have you gone to a garden center or hardware store and seen the seed display either outside or just inside the doors to go outside? This is a recipe for disaster and probably why you saw poor germination results from seeds in the past.
You want to keep seeds out of direct sunlight in a cool spot that maintains a fairly consistent temperature. Consider a cold closet, a basement, or a room on the north side of your home that remains cool year round.
Seeds that have been sufficiently dried can also be stored in airtight containers inside of a refrigerator or freezer. The key here is to ensure there isn’t any moisture on the seeds, so you may also want to add some moisture gel packs to your seed storage containers.
How do you decide if you should store your seeds in the fridge or freezer?
Storing seeds in the refrigerator, or below 40°F, can help to extend the life of seeds for a few years. This is the best method for storing seeds that cannot freeze known as recalcitrant seeds. These are typically tropical varieties such as avocado, cacao, coconut, jackfruit, lychee, mango, rubber, and tea
Freezing temperatures below 32°F are used to store orthodox seeds for several years. Orthodox seeds make up 80% of the seeds in the world and are the seeds most growers are familiar with.
To recover seeds from the freezer for use:
- Set the jar out on a kitchen table or shelf for 12 hours so it can reach room temperature. This will prevent moisture from condensing on the seeds.
- Expose the seeds to air by opening the lid for a few days before planting.
Refrain from moving seeds from the freezer to room temperature more than once, as each transfer will reduce the viability of the seeds.
How long can garden seeds remain viable?
Many seeds will remain viable for several years at room temperature, but some do not fare as well. Crops like carrots, parsnip, onions, and leeks are notoriously short lived. For these, freezer storage is best. Seeds from these varieties that are stored at or near room temperature will quickly lose their ability to germinate and grow.
As seeds age, their germination rate naturally declines. All seeds will stay viable for at least a year, and storing seeds properly can allow many seeds to remain viable even longer. Here’s an idea of how long different types of seeds can last with optimal storage conditions:
Short-lived Seeds (1 to 2 years):
- sweet corn
Intermediate Seeds (3 to 4 years):
- cabbage family (broccoli, Brussels sprouts, cabbage, cauliflower, kohlrabi, etc.)
Long-lived Seeds (5 to 6 years):
If you want to extend the life of your seeds, an easy method is to place your paper seed packets in a glass Mason jar, close it with an airtight lid, and keep them store in the refrigerator.
You also want to ensure you purchase your seeds from a trusted source that has stored them properly. Here at Kitchen Botanicals, we ensure we provide you with the freshest seeds possible that are stored in a temperature controlled environment away from direct sunlight. Our seeds are tested annually to ensure a minimum 50% germination rate.
What is your favorite method for storing seeds? Tell us in the comments below.