Like any other heirloom, heirloom vegetables have been passed down through generations. Their seeds are some of the oldest varieties of vegetables available. They are not used by large industrial farms, but rather by home gardeners. Some common heirloom vegetables grown in small gardens are tomatoes, corn, beans, kale, eggplant, squash, lettuce and even potatoes.
To qualify as heirloom vegetables, the variety must have some historic value. The oldest varieties date from prehistoric times. If the vegetable is grown in an industrial setting, it is no longer classified as heirloom.
The classification of heirloom vegetables means that they are open-pollinated. The seeds that a plant produces can be harvested and saved to create a look a like plant the following year. This ability to reproduce a virtual clone gives heirloom vegetables the label "true to type."
Because they are pollinated in such a way, heirloom vegetables tend to produce foods that have a superior taste and texture to hybrid plants. Farmers who grow the vegetables choose the best plants to use for seed harvesting. Only the seeds that came from the juiciest, most vibrant and largest producing plants will be saved. This picking and choosing has kept only the best plants in circulation and taken the weaker ones out with n a forced "survival of the fittest" technique.
The long history behind perfecting the plants make them genetically hardy. Plants of an heirloom variety are more likely to grow the same under the same conditions. With hybrids, five plants in the same garden may all look different and grow varying numbers of vegetables. Heirlooms are much more likely to appear as virtual twins given the same conditions.
The one downfall to heirloom vegetables is that they are not particularly resistant to pests and diseases. Since they were bred for taste, the overall hardiness of the plant has been somewhat sacrifices. They tend to require a bit more care and love to grow well. Watering should happen near the root only as water on the leaves can contribute to disease. They should be planted on a mound and given cages when appropriate.
When choosing a variety of heirloom vegetables to grow, research is key. Many commercial seed companies will be able to provide recommendations on what vegetables will be best suited to a particular region and soil. Apart from companies, seed exchanges are one of the most popular ways to find the perfect vegetable. These societies are dedicated to preserving the heirloom variety and offer resources and seed packets to those interested in helping with their mission.