Absolutely not. Although some people may tell you that’s a requirement, they’re just confused or oversimplifying. Trust me, there’s no International Registrar for Heirloom Plants that’s charged with officially defining the term – and age is relative, in any case.
Some plants like peonies and apples will live for a very long time, even in a totally abandoned garden, while other plants like dahlias and tomatoes will disappear most places unless someone saves, stores, and replants them every year. This means that 50-year-old peonies are relative youngsters compared to the many that survive from 100 or even 150 years ago, while 50-year-old dahlias are already hard to find, making them, in effect, much older.
It’s sort of like the way it is with dogs. It doesn’t make sense to define an “old” dog as one that’s at least eight years old because Irish wolfhounds rarely live that long while Chihuahuas can live to be twice that age.
That’s why I believe that insisting on a specific cut-off date for heirloom plants is misguided, and that rarity or endangeredness has to be as much a part of the definition as age itself. Heirlooms have been handed down because they’re wonderful plants, and the older they are the more they allow us to experience the incredible diversity of the past. (Hence our OHG tagline, “So Much More than New.”) But if we don’t grow and care for heirlooms, even the toughest of them will eventually be lost, and the ones that are most in need of our care are the ones that are the rarest and closest to extinction – even if they’re not yet 50 years old.
(You might also enjoy reading my earlier newsletter article, “Heirloom Myth-Busting #1: Are They Heirloom, Heritage, Antique, Vintage, or Historic Plants?”)