Seeds are not usually confined to their use during the planting year. Most last at least two years, sometimes as long as 10 years or more. Proper storage will help extend their lives. It is helpful to know both how to store them and how long they keep for, and perhaps you can several years use or more, out of a single seed packet.
Best practices for seed storage:
- Somewhere Dark
- Cool (Ideally, 40F)
- Airtight container (jars or ziplock baggies)
Before counting on your seeds when they are past their prime, you can do a germination test to determine viability. Pick out about 10 seeds from your packet and place them in moist layers of paper towel, place them in an unsealed plastic bag and set the bag in a warm, sunny location. Check the moisture of the paper towels daily, and also check for germination. Once you notice a root poking through the seed coat, the seed has germinated. Wait a week, then count to see how many seeds have germinated to determine if you should order new seeds or proceed with these. If you plan to do your germination test right before you need to start seeds for the season, you can use the sprouted seeds from the paper towel and place them in your seed starting medium and allow them to continue growing. Generally, a germination rate of 80-90% is acceptable, anything less than 50% and you will probably want to buy fresh seeds. If some seeds did not germinate but you’d still like to use them, you may wish to plant the seeds more thicker than usual (if broadcasting over your garden bed), or include an extra couple of seeds in each cell if starting seeds indoors to make up for what may not sprout.
Lifespan of seeds: The lifespan of seeds can vary, depending on your storage conditions, so the chart below is simply a guideline. Always do a germination test if you are unsure. Keeping your seeds in their best environment at all times will help ensure a longer lifespan, as each time they are removed from ideal storage conditions, they will experience a decline in viability. The more exposure to adverse conditions they experience, the sooner they will fail to germinate all together. The exposure to adverse conditions can also contribute to a lack of vigor, or the ability of a plant to grow well. Seedlings that don’t have great vigor will often grow slowly, look stunted, succumb to diseases easier, or be deformed. So even though your seeds may have germinated, the next challenge is getting them to grow strong, uniform, and healthy – but if they are too old, with even the best care they may not thrive.
|Brussels sprouts||4 years|
|Corn (sweet)||2 years|
|Oriental greens||3 years|
|Squash (Summer & Winter)||4 years|