Heirloom (or heritage) plant varieties and seed is one that has been valued by a family or community group, tenderly and carefully preserved, and handed down from generation to generation. They tend to be prized for specific traits they possess such as appearance, fragrance, and flavor. An heirloom seed must be an open-pollinated variety.

The oldest known reference using the word “heirloom” as an adjective for seeds, plants and bulbs is found on page 30 of a book entitled, Pioneer American Gardening, compiled by Elvnia Slosson, copyright 1951, Published by Coward-McCann, Inc., New York.