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What Are Heirloom Vegetables? Benefits And Cautions

What Are Heirloom Vegetables? Benefits And Cautions

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Sydney Bosque
Latest posts by Sydney Bosque (see all)

There are so many terms to describe fruits and vegetables that reading labels can become overwhelming. They don’t stop in the produce section, either. Labels claiming to be made with organic apples, non-GMO wheat, or heirloom tomatoes flood the inner aisles of every grocery store.

How are we supposed to keep them all straight? What are heirloom vegetables, and how do they compare to other labels?

Heirloom refers to a plant that is open-pollinated and at least 50 years old. Open-pollination is only possible in non-GMO plants and plants that are not hybridized for commercial production. However, not all non-GMO plants are heirlooms.

So, what makes heirlooms so special?

Classifying Heirloom Vegetables

Any type of plant can be an heirloom, but vegetables are the most readily available and interesting to consumers. The same rules that apply to classifying an heirloom vegetable also apply to flowers, fruits, and grains.

You can purchase heirloom vegetable seed variety packs online (link to Amazon).

Open Pollination

This is the most basic requirement for classifying a variety as an heirloom. Open pollination means the plants are pollinated naturally through a variety of methods:

  • Self-pollination. Flowers that pollinate themselves without the need for any outside force are classified as self-pollinated. Self-pollination is not cross-pollination. These seeds are the most likely to remain true-to-type.
  • Wind. Flowers that rely on the wind to blow pollen between flowers are classified as wind-pollinated. Wind pollination is a type of cross-pollination.
  • Insects. Flowers that rely on bees, butterflies, wasps, and other insects are classified as insect-pollinated. Insect pollination is a type of cross-pollination.

Self-pollination and cross-pollination are both types of open pollination. The plant is able to reproduce new seed each year by relying on natural sources of pollination.

Open-pollinated seeds should be true-to-type as long as they are not planted too close to related species.

The difficulty with open-pollinated plants is that they cross easily with similar varieties. This is why gardeners who save seed must separate different varieties to make sure they do not cross with each other.

But, this begs the question: If open-pollinated seeds can create open-pollinated hybrids, why aren’t hybrids classified as heirlooms?


All heirloom seeds are open-pollinated, but not all open-pollinated seeds are heirlooms. An heirloom variety must be open-pollinated and at least 50 years old.

Most heirloom seeds are saved year after year in home gardens, and the families or communities can trace the variety back decades, if not centuries.

Examples of heirloom varieties include:

  • The Nigra Hollyhock planted by Thomas Jefferson at Monticello.
  • Ferro Medio, an ancient grain found in the tombs of Egyptian kings.
  • The Mortgage Lifter tomato, a variety founded by a plumber in the 1930s that was so prolific he paid off his house with the proceeds from seedling sales.

Many heirloom varieties started off as hybrids between two or more heirloom varieties, like the Mortgage Lifter. After years of careful breeding and selecting for specific traits, a plant breeder will be able to create a variety that is stable enough to reproduce itself true-to-type.

After the variety is stable, it takes 50 years before it can be classified as an heirloom. So, hybridizing a plant does not destroy or create an heirloom. Any open-pollinated plant that is 50 years old or more is an heirloom.

Benefits of Heirloom Vegetables

Heirloom vegetables offer multiple benefits including improved nutritional content, flavor, and variety.

So, why are people so enthusiastic about ancient vegetables?

Heirloom varieties have three key characteristics that make them superior to other varieties:


When breeders create varieties for commercial production, they have to select for traits that make the produce shelf stable and uniform. It’s also important to have produce that ripens at the same time so growers can harvest during a short time period.

Unfortunately, when you select for thick skin, durability, high yield, and short harvest periods, you lose some of the qualities that make vegetables nutritious.


Another byproduct of breeding for shelf stability and yield is the loss of flavor. This is not so much a genetic characteristic as it is an environmental one.

Flavor depends heavily on the correct growing conditions, healthy soil, and the proper harvest time.

Most commercial crops are grown in the correct climate, but the soil is depleted and artificially fertilized, while the produce is harvested a few weeks before the crop is ready in order to preserve shelf life, which doesn’t allow for the natural ripening process of increasing sugar content.

Heirlooms are usually not suited for commercial growing operations, so they are typically grown by local farmers who are passionate about healthy soil and improving flavor.

While many consumers believe it is the genetics of an heirloom that cause it to be more flavorful, it is actually the simple fact that they are grown correctly.

Many commercial hybrids would be more flavorful if they were grown by local growers because they would have healthier growing conditions.

It is worth noting that some heirloom varieties were specifically bred for incredible flavor, but as you continue to select for improved flavor, you can lose nutritional value and shelf stability.


Heirloom veggies open a world of possibilities in the kitchen. We have, on average, 5-7 varieties of tomatoes in the grocery store. If you wanted to grow your own heirloom tomatoes, you would have to choose from 35,000 different heirloom varieties that have been preserved across the globe for generations.

Perhaps the most interesting feature of heirloom veggies is the unique shapes and colors among the different varieties.

Colorful vegetables indicate flavor and nutrition, which is why many associate heirlooms with health benefits.

As you browse through an heirloom seed catalogue, you can find pictures of purple sweet potatoes, black radishes, swirling Romanesco broccoli, and multicolored popcorn. Specialty seed sources may even list ancient grains, like purple wheat or farro.

These unique characteristics are what makes heirloom vegetables both desirable by consumers and impossible for large-scale growers. This is why it is so difficult to find heirloom produce in the grocery store.

The Downside to Heirloom Vegetables

All good things must have a downside. While the hype around heirloom vegetables has raised them to the pedestal of a superfood, there are a few valid reasons why growers tend to stick to more stable hybrid varieties.

Pests & Diseases

Most commercial hybrids have been bred to resist pests and diseases, which is part of what makes large monocrops possible. When you cross two varieties to create a hybrid, you get a phenomenon known as hybrid vigor.

This is basically an extra oomph of energy each plant has due to the mixing of two specific species.

This vigor translates into increased pest & disease resistance, as well as improved overall health. These factors greatly influence large-scale growers, because fewer pests and diseases means fewer sprays and crop losses.

Irregular Harvest Dates

Heirloom plants have a longer, less productive harvest season. This is not because heirlooms are inferior, but rather because commercial hybrids have been overbred for production.

Heirloom varieties were perfect for kitchen gardens, because they would produce a few fruits at a time over the course of the summer and fall, rather than one large harvest in a two-week period.

If you are growing your own plants, heirlooms are well-suited to a slow and steady harvest schedule. However, if you like to can or freeze large batches of tomatoes or other fruit-bearing vegetables, you may need to plant more plants to get enough of a harvest to make recipes in bulk.

Irregular harvest dates is one of the main reasons heirlooms are not grown commercially. Harvest is one of the most expensive tasks for growers, which is why they need to grow vegetable varieties that ripen during a small window.

Heirloom plants are trending, and for good reason. They are healthier, more flavorful, and much more interesting to look at than a boring red tomato. However, they can be more difficult to grow and the seeds can be harder to find.

If you do decide to grow heirlooms, read through our articles on starting tomato seeds, improving soil, and making the ideal compost so you can give your heirloom plants their best chance.