Heirloom varieties of fruits and vegetables are varieties that have been passed down within families and communities from generation to generation. They are usually older varieties from before the rise of hybridization and industrialized agriculture.
Heirloom seeds are open pollinated, which means that seeds of two parents of a particular variety will produce a plant of the same variety. In contrast, hybrid varieties are produced from two different parent varieties and the seeds do not produce the same variety.
For thousands of years before the existence of seed companies, gardeners saved seeds from their best plants to use the next year. Over many generations, plants with the best characteristics of flavor, color, texture, and resistance to local pests and those that did best in local climate conditions were selected for seeds and the varieties became well suited to local tastes and growing conditions.
Hybrid varieties began to be developed after WWII. They were bred for traits that are useful for commercial agriculture such as fruit ripening at the same time, uniformity of size and shape, and the ability to withstand shipment over long distances. Hybrids are usually picked while still unripe and ripened in transit through the use of a gas. While these characteristics allow people to have fresh vegetables year round, flavor is sacrificed.
For the home gardener, these characteristics aren’t as important and heirloom vegetables may be a better choice. It is usually an advantage for vegetables to ripen over a longer period of time rather than all at once. Vegetables that ripen naturally on the plant will usually be more flavorful and nutritious.
In the decades after WWII, seed companies gradually stopped selling heirloom varieties in favor of hybrids and many heirloom varieties have been lost. In recent years many people have recognized the importance of heirloom varieties and are working to save them. The Seed Savers Exchange, founded by Kent Whealy and Diane Ott Whealy, was the first organization dedicated to the preservation of heirloom varieties and there are now many other seed banks, seed sharing programs, and seed companies selling heirloom varieties.
Heirloom fruit and nut trees are usually propagated by cuttings and there are numerous sources on the internet.
Seed Sources for Heirloom Seeds
Seed Savers Exchange - www.seedsavers.org
Baker Creek Heirloom Seeds - www.rareseeds.com/
Bountiful Gardens - www.bountifulgardens.org
Sustainable Seed Company - www.sustainableseedco.com