Answer: Many seeds will remain viable for a number of years if they have been stored properly (e.g. in a closed container in the refrigerator), but the viability does decrease over time. One way to check viability is to presprout some on a damp paper towel enclosed in a plastic bag and set in a bright spot out of direct sunlight. This "test" will show you approximately what proportion of the seeds are still good so you can tell whether it is time to get new seeds or not.
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