Long Term Storage of Seeds 

2020 was the end of the world as we know it — the disruption of everything we know. It brings home the points about self-sufficient living and taking back control over food production. In this section, we discuss the long-term storage of seeds and the risks that they can bring. 

 Focus on Temperature and Humidity

Tip:  The ideal conditions to store seeds are in the dark, at temperatures below 50°F and with humidity at 50 percent or less.

 Temperature: 

For most seeds, 50°F or below is ideal for long-term storage. The cooler temperature helps keep the seed in dormancy.

 Moisture/Humidity: 

Ideally, you want to keep stored seeds in an environment with less than 50 percent humidity. It would be best if you had some moisture to keep the living parts of seeds alive but not so much humidity that mold or fungus destroy the seeds. 

 Sunlight 

Many seeds activate when the amount of sunlight increases. That is a natural process in spring when the days start to become longer. That shift in light can cause seeds to activate. For that reason, store seeds in darkness. 

 Declining Germination Rates

For the highest germination rates, use seeds the first year that you harvest them.   Almost any seeds will survive 1-2 years, but as time passes, the germination rate of the seeds begins to drop. However, some successes and failures are also due to the plant. 

Onions, parsley, spinach, parsnips have very short shelf lives. These are plants that drastically drop in germination rate after only one year of storage. 

Corn, legumes, okra tend to be okay through two years of storage. Yes, you can store them longer but fewer tend to germinate. 

If you store seeds in the freezer or fridge, place the seeds in an airtight container (e.g. resealable zipper bag or jar).  Add desiccant to help control moisture levels in the container. 

 General Guide for Shelf Life of Seeds 

Carrots, turnips, rutabagas, and leek seeds can last three years with a high germination rate. 

Peppers, Squash/pumpkins, artichokes, and watermelon can last four years with a reasonable germination rate. 

Five years is a general max. Those plants that can manage a high germination rate with five years of storage include Beets, tomatoes, cucumbers, celery, the majority of brassica, and lettuces. 

 Should I Freeze My Seeds? 

You can. Every seed bank around the world freezes its seed libraries. What you want to guard against if you freeze seeds is that humidity remains below 50 percent. 

 Should I Store Seeds in the Fridge?

You can. The problem with the fridge and seed storage is that the temperature fluctuates every time you open the door. Storage in the freeze is better because the temperature in the freezer remains somewhat constant.