An heirloom tomato, also called heritage tomato, is an open-pollinated (pollinated by insects, birds or wind) non-hybrid heirloom cultivar of tomato. Heirloom tomatoes have become increasingly popular and more readily available in recent years. They are grown for a variety of reasons, such as historical interest, access to wider varieties, and by people who wish to save seeds from year to year. These odd looking tomatoes are also known for their taste, which is widely perceived to be better than modern tomatoes. Almost every time I go the FARMERS MARKET, I can always be sure to find many different varieties of colorful heirloom tomatoes.
Heirloom tomatoes lack a genetic mutation that gives standard tomatoes an appealing uniform red color while sacrificing the fruit’s sweet taste. Varieties bearing this mutation, which have been favored by industry since the 1940s, feature fruits with lower levels of carotenoids and a decreased ability to make sugar within the fruit. An heirlooms appearance is a signature variety of colors, shapes, flavors, sizes and is prone to cracking. As with most garden plants, these tomatoes can be acclimated over several gardening seasons to thrive in a geographical location through careful selection and seed saving.
Heirloom seeds “breed true,” unlike the seeds of hybridized plants. Both sides of the DNA in an heirloom variety come from a common stable cultivar which combines different cultivars. Heirloom tomato varieties are “open pollinating”, but cross-pollination is very rare without human intervention.
Collecting heirloom seed is as easy as picking a ripe tomato, mashing it into a jar till less than half-full, fill with water, shake from time to time and allowing it to decompose for 1-6 days until seeds sink to the bottom, then rinsing until the seeds are clean, and drying them. This decomposition is beneficial because it discourages transmission of diseases to the seeds; the drying promotes better germination, and the seeds are easier to separate when they are clean.
Growing heirloom tomatoes can add interest and variety to any garden. These varieties are more common nowadays so check out the selection at your local nursery or go online and research what varieties will grow in your area and start seeds this coming spring.