Germination Tests, Shelf-Life and Seed Storage
Seed germination and shelf-life
Germination tests are carried out regularly on seed lots.
We guarantee high germination rates in the year of seed purchase. Beyond that year, it depends on the variety of vegetable and how you store your seeds. Germination rates decline year on year. Parsnip seeds, for example, only retain a high germination rate in the first year, whereas squash can retain its germination potential for 5-10 years.
Therefore, we recommend that you note the year of purchase on your seed packets, store them in the best possible conditions and consult a seed germination chart for your variety of vegetable.
The following list is for information purposes only:
Seed germination shelf-life*
Lettuce | 3 years
Sunflower | 7 years
Beans | 4 years
Peas | 3 years
Tomato | 4-10 years old
Squash | 6 years
Cucumber | 10 years
Spinach | 2-5 years
*May be increased or decreased due to storage conditions
If you are unsure about the viability of your seeds, perform a germination test. It's simple, put some seeds inside a sheet of paper towel, cloth or a tissue. Soak the seeds wrapped in paper and place them in a non-watertight plastic bag. Put the bag somewhere warm, like the top of your kitchen cabinets or refrigerator. Leave them for the usual germination time then take the seeds out of the paper to check if they have germinated and if the germination rate is satisfactory.
With these few tips, you will be able to better plan your seed purchases and avoid disappointment in the garden come spring.
Storing seeds
To keep seeds as long as possible, store them away from the elements that trigger germination: heat, humidity and light.
Seeds should be stored in a cool, dry and dark place. Temperatures below 10°C are ideal.
The cooler the temperature, the longer the seeds stay viable. You can put them in the refrigerator but in this case, be sure to place them in an airtight container to protect them from humidity and always wait until the jar has risen to the same temperature as the ambient air before opening the jar in order to avoid condensation on the seeds.
Julie Ross - Artisanal seed producer since 2009