wheatgrasskits wrote:up to 5 years, the seeds will still germinate after that especially if kept in a cool dry place, but germination may start to decline after the five years!
Short Answer:
In general we recommend changing out the canned seed every 5 to 6 years.
Long Answer:
Both storage conditions and species play an important role in long-term viability.
Species
Most of the popular vegetable seeds store well, however onions and lettuce deteriorate more quickly. Other species such as cabbage and beet seed can easily last for several years with no special care.
Storage Conditions
Always store seed sealed, in a dry place, in the dark, and at a cool temperature. The colder the better. A cool basement is good. If you have sufficient space, a fridge or freezer is even better. Yes, you can freeze the seed IF IT IS WELL DRIED AND SEALED UP.
Under ideal conditions, most of the seed in this can will last well over 5 years.
We recently tested the last of our oldest canned seeds. This can was over ten years old, stored at room temperature. We found most of the seed still good, but the beans had died.
Another recent test of an early batch - also tested at about ten years, also stored at room temperature, also tested mostly good. In this batch the beans we good but the lettuce had died.