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What Are Heirloom Tomatoes? FAQs

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Updated 12.21.23

Amid all the tomato gardening chatter, there’s one question that’s asked over and over: what are heirloom tomatoes? And why all the fuss? Read on to learn what are heirloom tomatoes and why you may want to grow them in your garden.

Q. What are heirloom tomatoes and how are they different from regular tomatoes?

Many refer to the symmetrical red globes in the grocery store as “regular” tomatoes. Most of those fruit are hybrids – the result of intentionally cross-pollinating two different tomato varieties. Hybrids are bred for durability. They are cultivated both commercially and in the home garden.

Heirloom tomatoes, on the other hand, are tomato varieties that have been reproduced without cross breeding. A tomato is considered an heirloom if it has been cultivated true to the original for at least 3 generations. Some heirloom tomatoes have a history that spans hundreds of years.

Q. What are some other names for heirloom tomatoes?

In the U.K., heirloom tomatoes are called heritage tomatoes. And across the world, you may hear about open-pollinated (OP) tomatoes. Heirloom varieties are classified as open-pollinated (OP). But all OPs are not heirlooms.

The difference has little to do with seed purity and more to do with documentation. An heirloom is an OP tomato with a verified history. It has been documented and verified for purity when passed down within a family or community, like a treasured quilt or precious diary.

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Q. What is so special about heirloom tomatoes?

Gardeners go to a lot of effort to breed and raise heirloom tomatoes. The plants are individually grown. Their seeds are harvested by hand to ensure that they remain true-to-type.

There is reason for all that work. Each heirloom has desirable traits – the Brandywine Sudduth’s prolific, 1–2-pound fruit … the Chocolate Stripes’ rich, complex flavors … Sunset Red Horizon’s lengthy production season.

Q. What else makes heirloom tomatoes different from hybrids?

Heirloom tomatoes are less resistant to diseases, pests, and weather fluctuations than cross-bred varieties. And they have thinner skin. They’re particularly prone to cracking.

But heirlooms tomatoes also have gorgeous colors: deep reds, bright yellows, bright purples, lemony-greens, coffee-and-chocolate browns, bold stripes, multi-hued strands. The colors indicate higher levels of carotenoids – inflammation and cancer-preventing compounds. Those same compounds that produce heirlooms’ more intense flavors.

Q. What are heirloom tomatoes used for?

Like hybrids, they can be eaten raw or cooked.

Q. What should you be aware of when growing heirloom tomatoes?

When it comes to harvest time, heirloom tomatoes may trick you into leaving them on the vine too long. Heirlooms ripen from the bottom up. They may have green shoulders at the top of the fruit while the bottom is fully ripe.

Don’t be fooled. The truth is that when an heirloom looks perfectly ripe, its cellular structure is already breaking down. That means heirlooms have less countertop staying power than their hybrid cousins.

Go ahead and pluck that heirloom off the vine, just before they look like they’re ready to harvest. Or leave it on the vine until it looks ready … but don’t let it hang out in your kitchen. Serve it immediately.

Q. How many heirloom tomato varieties are available?

Best estimates are that there are 3,000 known heirloom tomatoes cultivated worldwide. Our friends at TomatoFest offer a selection of more than 650 heirloom tomato varieties.

Q. Why are heirloom tomatoes illegal?

Illegal heirloom tomatoes – huh? Home gardeners routinely save their seeds and use them next season. Plenty of these law-abiding folks share their tomato seeds with other gardening aficionados. And by their very definition, heirloom tomatoes are passed down from generation to generation.

At issue is unregulated seed swapping, which is against the law in a handful of U.S. states and plenty of other countries. Government entities (and in the U.S., the states) regulate germination rates, weed/seed rates, and pesticides. If your production isn’t supervised, then wayward heirloom tomato seeds can produce wayward crops which can ultimately threaten the food supply.

And can threaten the commercial seed industry. Producers who own a seed patent may object to others lifting those rights, particularly when they produce and sell the seeds for profit. “If a breeder has created a whole new plant species through genetic engineering, he can prevent others from the reproduction, use, sale and distribution of this newly invented plant,” explain the good folks at Garden Organic. “Agribusinesses, such as Monsanto and Syngenta, frequently apply for patents on the seeds and plants they have genetically engineered. It gives them monopoly rights subsequently over all seeds, plants, and fruits with the same trait.”

The seed patent situation is tricky business. Yet unlike hybrids and GMOs, heirlooms are open-pollinated varieties that cannot be patented. “To get a patent or Plant Variety Protection (PVP) in the U.S., the application must be filed within the first year of selling or distribution for the variety,” explains patent attorney James Weatherly. “For these older varieties, that means mostly likely they are not eligible for patent or PVP.” While that may be disappointing for a commercial grower, it’s good news for heirloom tomato lovers and home gardeners.

If you’re worried that your local sheriff will stop by your backyard while you’re setting out tomato seedlings in the ground – and force you to yank them out of the ground and throw them onto the compost pile – then the solution is simple. Patented seeds are labeled. Check your tomato seed labels and the information in seed catalogs to determine whether or not they’re patented – and then be sure not to save those seeds.

Q. Why are heirloom tomatoes so expensive?

Heirlooms are grown carefully, siloed by variety to keep each cultivar true to its original. Gardeners meticulously collect seeds each year by hand. The crop is then scrupulously planted each season, generation after generation, sometimes for hundreds of years. Overall, heirloom tomatoes are more prone to disease and pests and less prolific than their hybrid cousins. Those that do make it to market do not store or ship well.

Combined, those traits mean fewer heirlooms are available for consumers.

That means heirloom tomato seeds and plants are a bit more expensive than hybrids. And fresh heirloom tomatoes? They’re usually a significant bump higher in price.

Which makes sense, because heirloom tomatoes are high maintenance.

But they’re worth it.

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