When you think of an “heirloom plant”, you may be imagining a plant that has changed little in over a hundred years—something our great- great-grandparents would have farmed and eaten. However, the definition of an heirloom plant is a bit more fluid than that, and not only includes edibles but also plants such as flowers, herbs, bulbs, and shrubs. In fact, there is no singular consensus on how many years a plant has to have remained unchanged to be considered an heirloom. Some groups use cut-off dates—meaning dates after which the plant has not changed. For instance, 1940 is the cut-off date used by the Southern Exposure Seed Exchange in Virigina.