How long do seeds remain viable in proper storage?
Written by
Olivia Mitchell
Reviewed by
Prof. Martin Thorne, Ph.D.The length of time a seed can remain viable is highly variable, depending on the seed species and the storage methods used, although these methods are optimal. Tomato and cucumber seeds can be stored effectively for 5-10 years, while onion and spinach seeds can be stored for only 1-2 years. I have personally germinated tomato seeds that were stored for 8 years under appropriate storage conditions. Therefore, the methodologies used for seed storage can drastically influence these durations.
Longevity Champions
- Tomatoes and cucumbers maintain 70%+ germination for 5-10 years
- Store in vacuum-sealed glass jars below 50°F (10°C)
- Peppers and beans remain viable for 3-5 years in HDPE containers
- Add oxygen absorbers to prevent oxidative degradation
Short-Lived Varieties
- Onions and spinach lose viability rapidly within 1-2 years
- Require refrigeration at 40°F (4°C) with desiccant packets
- Parsnips and corn need annual viability testing
- Store in small batches to minimize repeated container openings
Storing seeds properly can double the normal viability dates of most seeds. Temperature-controlled places greatly reduce metabolic activities. An airtight container prevents oxygen damage to the seeds and the infiltration of moisture. Following these approaches allowed my bean seeds to last seven years instead of four. The choice of where and the way I stored the seeds made this possible.
Test viability yearly for major varieties. For the germination test, put ten seeds on damp paper towels. Discard any varieties that achieve a germination rate below 50%. I test my tomato seeds every winter before planting season. This will not guarantee that you will not waste garden space on non-viable seeds.
Utilize a seed rotation system for annual varieties. Use the older seed first and store the newer seed for future use. Mark the bag with the collection year. For instance, I save onion seeds for replanting only after one year, while tomatoes last for many years. This is an efficient process for managing your seeds.
Read the full article: 10 Best Seed Storage Containers
