What qualifies as an heirloom seed?
Kim Schwind The definition of ‘heirloom’ is not always agreed upon — some say an heirloom variety must be at least fifty years old, some say it should be older. But generally speaking, an heirloom seed comes from a plant variety that has been passed on through several generations within a family or community. The truth is seeds don’t expire. They lose viability if stored improperly. While most seed companies will tell you to replace seeds every 2-3 years, those seeds will keep for decades and will germinate when planted if kept in a cool, dark, and dry place.Most seeds will store the best below 40 degrees Fahrenheit with less than 10 percent humidity in an airtight container in a dark environment. Your freezer or refrigerator are great places to store your seeds, just make sure they’re shielded from light.The lifespan of heirloom seeds depends on the type of seed. Some seeds can remain viable for several years, while others may last 10-15 years or even longer. Proper storage is vital in ensuring that your seeds stay in optimal condition and have a high germination rate.Seeds that have been stored in a cool, dry place are generally viable for at least a year past the season for which they were packaged and may be good for up to five years.A dry seed will last much longer at room temperature than a moist seed in the fridge. Cool and dry are the two ideals for most of the seed we are concerned with. As a rule of thumb, the storage life of a seed is doubled for every 5ËšC drop in temperature and 1% drop in moisture content.