What does “heirloom” vegetable mean?
There are many opinions on what is an heirloom vegetable. The most common definition: open-pollinated plants (pollination by wind or insects) which are at least 50 years old, and which have been grown continuously. This would include varieties recently reintroduced by seed companies, but which were previously unavailable through the seed trade. Instead, they were preserved over the years by families, or by ethnic, religious, or tribal groups who handed down the seeds from generation to generation. But it also includes varieties that were commercially available in the 19th and early part of the 20th century. The variety must have a history of its own.
This is a broad definition to many. There are those who consider a variety that was available or is now available commercially not to be a true heirloom. Others dislike the “grown continuously” label because it excludes those that were lost and rediscovered. A good example of a lost variety is the Anasazi bean uncovered by archeologists. It had not been grown for 400 years.
Left out are the “modern heirlooms.” These are the new open-pollinated varieties that are the product of accidental natural crossing or intentional cross-breeding. These natural hybrids have the ability to breed true to type. Many of these will be passed on and fifty years from now will earn the title “an heirloom variety.”