What is an Heirloom Tomato?

An heirloom tomato is a variety of tomato that has been passed down through generations of growers, typically for at least 50 years. These tomatoes are known for their diverse colours, shapes, sizes, and flavours, which set them apart from the more uniform, commercial varieties you often find in supermarkets. Here's what makes heirloom tomatoes special:

1. What Defines an Heirloom Tomato?

• Open-Pollinated: Heirloom tomatoes are open-pollinated, which means they are pollinated naturally by insects, birds, wind, or other natural means. This allows the plants to grow true to type from one generation to the next. If you save seeds from an heirloom tomato and plant them the following season, they will produce plants that are almost identical to the parent plant.

• Not Hybridized: Unlike hybrids, which are created by cross-breeding two different tomato varieties to produce specific traits (like uniform size or disease resistance), heirlooms have not been genetically modified in this way. They are more genetically diverse, leading to a wider range of flavors, colors, and shapes.

• Historical and Cultural Significance: Many heirloom varieties have interesting histories. Some have been passed down within families or communities for generations, while others were developed by farmers and gardeners and kept alive by seed-saving organizations. They often carry names that reflect their origins or the people who grew them, such as Brandywine, Cherokee Purple, or Mortgage Lifter.

2. Categories of Heirloom Tomatoes

Heirloom tomatoes can be classified into a few different types based on how they have been maintained and shared over the years:

• Family Heirlooms: These are varieties that have been passed down within a family for generations. For example, a family might have saved seeds from the best tomatoes in their garden each year and handed them down.

• Commercial Heirlooms: These were once developed and sold by seed companies but have been kept alive over the years by enthusiasts. Even if they are no longer sold by the original company, they remain popular through seed exchanges.

• Created Heirlooms: These are deliberate crosses between two heirloom varieties or between an heirloom and a hybrid. After years of stabilization (usually 5–7 generations), the cross becomes stable enough to produce consistent traits, and it can be considered an heirloom.

• Mystery Heirlooms: These are accidental crosses that happen naturally, creating a new variety. Some of these turn out to be so desirable that they are saved and shared, eventually becoming recognized as a new heirloom.

3. Why Are Heirloom Tomatoes So Popular?

• Flavour: Heirloom tomatoes are often prized for their superior flavour. Because they are bred for taste rather than for storage or uniformity, they can have a richer, sweeter, or more complex flavor than many commercial varieties. Each type of heirloom can offer a unique taste experience, from tangy and tart to sweet and juicy.

• Diversity: Unlike standard supermarket tomatoes, which are bred to be uniform in size, color, and texture, heirloom tomatoes come in a stunning range of colours (red, green, yellow, purple, black, and more), shapes (round, oblong, ribbed), and sizes (tiny cherries to large beefsteaks). This diversity makes them a favorite among chefs and home cooks looking to add visual appeal and variety to dishes.

• Nutritional Value: The genetic diversity of heirloom tomatoes may also mean that they have a wider range of nutritional benefits. Different pigments in the skin (like lycopene, beta-carotene, and anthocyanins) are associated with various health benefits, and heirloom varieties can offer a broader spectrum of these nutrients.

4. Challenges of Growing Heirloom Tomatoes

• Disease Susceptibility: One downside to heirloom tomatoes is that they can be more susceptible to diseases than modern hybrid varieties. Hybrids are often bred to resist common tomato diseases like fusarium wilt, verticillium wilt, and blight, whereas heirlooms have not undergone this selective breeding. This means that growing heirlooms can sometimes be more challenging.

• Less Uniformity: Because they haven’t been bred for uniformity, heirloom tomatoes can be misshapen or have blemishes, which might make them less attractive in a commercial setting. However, for many people, this natural and imperfect appearance is part of the charm.

5. Examples of Popular Heirloom Varieties

• Brandywine: Known for its large size, pinkish-red colour, and excellent, rich flavour. It's often considered one of the best-tasting tomatoes.

• Cherokee Purple: A dark, purplish-brown tomato with a sweet, smoky flavour. It's thought to be an heirloom variety with a history tied to the Cherokee people.

• Green Zebra: This variety stays green when ripe, with yellow stripes. It has a tangy, zesty flavour that sets it apart.

• Black Krim: Originally from Crimea, this variety has a deep, dark colour and a savoury, almost salty flavour.

• Yellow Pear: Small, yellow, and pear-shaped, these tomatoes are sweet and mild, great for salads.

6. Preservation and Seed Saving

• Heirloom tomatoes play a crucial role in biodiversity. By saving seeds from heirloom varieties, gardeners help preserve genetic diversity, which is essential for food security. This is in contrast to the monoculture approach often seen in commercial agriculture, where a few hybrid varieties dominate.

• Organizations and seed banks, like Seed Savers Exchange and The Heritage Seed Library in the UK, work to preserve heirloom seeds, ensuring that these unique varieties remain available for future generations.

Conclusion

Heirloom tomatoes are more than just another type of tomato; they represent a rich history of agriculture, biodiversity, and flavour. Unlike commercial hybrids, which are often bred for qualities like shelf life and uniformity, heirlooms have been cherished for their taste, diversity, and uniqueness. Growing heirlooms is also a way to connect with the past and support the preservation of rare and distinctive plant varieties.

For those who value taste, variety, and history, heirloom tomatoes are a true treasure in the world of gardening and cooking.