The definition of “heirloom seeds” is a matter of debate. For our purposes, West Coast Seeds considers a plant an heirloom if it has been in cultivation for 50 years or more, although some people insist that 100 years is the magic number. Whichever period of cultivation is correct, it’s worth noting that modern industrial agriculture really began in 1945, following World War II. This was when farms in North America and Europe started growing more monoculture crops – one crop type growing in huge expanses of land. So in some ways, heirloom seeds can be considered “pre-war” varieties.
“Heritage” is a designation used more in the UK than in North America, but it means essentially the same thing as “heirloom.” It is sometimes used to describe an heirloom variety that has cultural or ethnic importance, as in Romano beans, as they have a direct lineage back to Italy. In the late 1800s and early 1900s, many immigrant families brought with them to North America varieties that had been cultivated for generations.
Just about all sources suggest that heirloom varieties must be open pollinated, and not hybrids. This works well if we use the 50-year definition, as hybrid vegetables didn’t really arrive in widespread agriculture until after 1951. Today, there are a handful of hybrids still grown since that time, but whether they can be considered heirloom hybrids is another matter.
The term heirloom is not just for vegetables, either. Many fruit trees, roses, and even livestock enjoy heirloom status, but it’s the veggies we’re interested in.
Heirlooms of all types are cultivars – that is, they are cultivated varieties (not wild) that have been deliberately selected for specific characteristics. When grown, harvested, and propagated correctly, those characteristics will be retained from one generation to the next. In theory, the heirloom tomato that was grown by your great, great, great grandmother will have the same leaf type as the one you grow in your garden this summer, and the fruits will be consistent in their flavour, texture, colour, and yield.
This genetic lineage that should be so consistent is not guaranteed. Plants grown side by side with other varieties are prone to cross pollination – the distance required between like vegetable types is known as “isolation” by plant breeders, and it varies from crop to crop, from several feet to several miles. The ways in which seeds are harvested and stored can also impact the subsequent generation of plants, as can viral diseases. Assuming, though, that they have been isolated, harvested, and stored correctly, and that they are free from disease, heirloom cultivars should be exactly what they claim to be.
Because they have been so carefully cultivated, nearly all heirloom varieties have traceable histories. In some cases, you can trace the history with genealogical precision. With others, though, the hunt for the original ancestor is more a matter of detective work. This is largely dependent on the quality of the written record, which, going back in time becomes vague at a certain point. Many heirloom tomatoes are listed simply as dating to “pre-1800.”
Why grow heirlooms?
Growing heirloom vegetable varieties (and saving their seeds from year to year) can be a fascinating, life-long hobby. It can even be a generational project in your family or neighbourhood. Experimenting with heirlooms can be a wonderful way to discover new flavours, growing techniques, and recipes. Heirloom varieties that have been grown for generations in one geographical region may have developed particularly good disease resistance, or tolerance for insects and weather extremes.
More than anything, keeping a wide range of heirloom vegetables (and flowers, trees, and livestock) growing from year to year allows us to maintain a wider gene pool for future generations. Vegetable varieties, after all, can become extinct just like any other living thing. It is thought that in the 20th century alone, around 75% of food crop varieties have disappeared. Because of the spread of industrial agriculture over the previous decades, it made more sense for farmers to focus on one main crop, and to mechanize their farms. As we look toward a future of more organic farming solutions, maintaining a strong and varied gene pool is obviously worthwhile.
So this year, consider growing some history. Think about saving some of your seeds for next year, even if it’s just an experiment. Share some seeds with your garden club, or get involved with seed conservation organizations like Seeds of Diversity.