If you are buying seeds, you may hear people talking about Heirloom Seeds or Hybrid Seeds. You may read it on a seed package or a catalogue. What does that mean? And does it matter if your tomatoes are hybrid or heirloom? The answer depends on what you ultimately want to do with your plants.
Heirloom seeds, sometimes called heritage seeds, grow heirloom or heritage plants. There are also heritage breeds of animals. People also talk about eating heirloom or heritage food. There’s no hard and fast rule, but generally when talking about seeds and plants, the designation refers to a variety that has been grown for fifty years or more. Some people argue that one hundred years should be the accepted period of time, but there’s a lot of varieties that would not be considered heirloom if there was a hard and fast rule of one hundred years. Monoculture increased after the Second World War, so generally heirloom seeds and plants date from pre-war years. Sometimes the definition of a heritage plant includes some cultural or ethnic consideration, but that is not universal. An example would be Romano beans that can be traced directly back to Italy of the late-nineteenth and early-twentieth centuries. Specific plants that had been grown for generations were brought with families emigrating to North America.
It is more than just the passage of time, though, that makes a specific plant or seed an heirloom or heritage variety. It means that the plant is very stable and its descendent will grow true to the parent. Some hybrid seeds have been available from seed companies and agriculture companies for over fifty years, but they are not heirloom. Heirloom plants are cultivated plants that have been selected over the years for specific desired characteristics. Heirloom plants will look the same over successive generations. They will have the same growing patterns, colour, flavour, and yield. When you save the seeds from your heirloom tomato this year, the tomato you harvest next fall will be the same. Heirloom plants, such as peppers, can cross-pollinate, meaning that they can pick up some characteristics of plants nearby. They can be marred by viral disease. Plants require space, and each plant has its own requirement for space from a similar plant, a distance that can vary from a few feet to a couple of miles. Nevertheless, providing the plant is given the space it needs, and it is free from disease, the plant will grow true to its parentage. Heirloom seeds can be traced back throughout generations. Some heirloom plants can be dated to a very specific place and time. Others are more vague. But they are a product of many years of saving the best.
Hybrid plants are created by crossing two varieties of a plant. The female flower of one variety is pollinated by the male of a different variety. The seeds from the female flower will have the characteristics from both varieties. The seeds from the resulting plant could be like one or the other of the parents.
Why do we care about heirloom seeds? Because varieties of plants are becoming extinct every day. Plants are becoming extinct at a very fast rate, and a lot of it has to do with humans growing predominantly one variety of a specific crop. We are losing genetic diversity in the plants we grow at an alarming rate. Agriculture is increasingly industrialised, and monoculture is increasingly the norm. If we lose the seeds that grow plants consistently over successive generations, we become dependent on the companies selling the hybrid seeds. We cannot plant the seeds from a hybrid plant and expect to grow the same plant. If we are dependent on companies or stores to supply seeds, we are vulnerable should they decide to consolidate their seed production. Saving heirloom seeds allows us some food security. Hybrid seeds often produce very well in a specific area. Over the generations, people have kept the best of their produce to provide the seed. These plants are adapted over generations to your climate, soil, and other growing conditions. One oft-cited example of the importance of maintaining genetic diversity is found by looking at bananas. Currently what we know as a banana is a variety known as the Cavendish Banana. If you go to a small roadside stand in a tropical country, you may find other types, and that comes as a surprise to many, but overwhelmingly the bananas that we grow worldwide are of the same variety. We have lost much of genetic diversity. The Cavendish banana, though, is gravely endangered by a new strain of Panama disease. Once a variety is extinct, it is gone forever. Relying on a very few varieties is leaving our food supply open to catastrophic shortages when diseases arise. Reducing the pool of plants from which to draw limits our ability to feed ourselves.