GMO vs. Hybrid Vs. Heirloom Vegetables – Know Before You Grow

A basket of vegetables in a garden
(Image credit: chanakon laorob)

Understanding the terminology used in reference to seeds will ensure you get exactly what you want. For instance, the differences between GMO and hybrid seeds revolve around science. Add heirloom seeds to the mix and the differences become even more unknown, albeit with a more natural genesis.

Basic Definitions of Heirloom, Hybrid & GMO

Farmers and home growers have many different seed choices. The selections depend upon many factors such as pest and disease resistance, variety, and origin concerns. Knowing which type is best for you will often hinge upon a true understanding of the definitions of the various types of seed.

What Does Heirloom Mean?

Heirloom seeds are the ones our grandparents grew. They may be hundreds of years or decades old. These varieties are making a comeback, supplanting the hybrid seeds that became popular in this century. Many gardeners feel heirloom seeds are more “natural” than hybrid or GMO.

Heirloom seeds are also referred to as open pollinated or standard seed. These have one or two specific traits that make them desirable. Because of open pollinating, over time the plants can cross pollinate with others in the same family, leading to unusual fruits. To avoid this, heirloom plants should be grown apart from others in the same group. This will prevent pollution of the strain, and keep viable the traits you want in the plant.

What Does Hybrid Mean?

Hybrid seeds are more expensive to produce than heirloom. This is because their production is in a lab and relies upon trials and careful scientific method to create varieties that have specific traits.

Breeders select male and female plants with the desired traits. Pollination between the two plants is carefully controlled. The result is an offspring that carries those wanted characteristics. Each plant must be hand pollinated, and the resulting plants go through many trials. In most cases, the offspring are adaptable to many stresses, are more uniform, and may be more consistent producers.

Are hybrid seeds GMO? No. Although science is involved in their production, hybrid strains are acquired through natural manmade manipulation. But this is one main difference between hybrid and heirloom. Heirloom seeds are not manipulated at all and are the result of natural selection.

What Does GMO Mean?

GMO seeds have some myths and misconceptions swirling around their creation. GMO seeds are genetically modified organisms. The process involves manipulating the genes in a plant variety through gene cloning and protein engineering. The result is a variety that may be resistant to an insecticide or herbicide, and may carry other specialty traits.

Most of the crops that are GMO are commercial ones such as cotton or sugar beets. In order to purchase GMO seed, a licensing agreement must be signed with the parent company. That means there are very few GMO seeds available to the home gardener. The majority of seeds we purchase are either heirloom or hybrid, the latter of which is designated by an F-1 label.

Common Misconceptions About GMOs

It is perfectly normal to be concerned about newly modified foods. Possible health and environmental risks top the list of concerns. In fact, many countries have banned GMO foods. In the U.S. the FDA does not require GMO foods to be labeled. This creates consumer fear and confusion. But the FDA also regulates the safety of such foods, while the EPA regulates the genetic material that goes into the plant.

The government has strict protocols and testing on the safety of GMO materials. Many environmental issues have been raised regarding GMO seed. In actuality, GMO crops have reduced tilling or disturbing the land which can lead to loss of topsoil and erosion. They utilize less pesticides, cause less fertilizer run-off, and have reduced CO2 emissions.

How Do They Differ?

GMO vs. Hybrid vs. Heirloom Plants

Even with some definitions, the selection of seed still carries some confusion. Rest assured there are few GMO seeds available to consumers. Hybrid plants have been around for a very long time and are proven winners due to the many trials they must undergo. Heirloom plants may be passed around from gardener to gardener and saved reliably every year.

Differences Between GMO and Hybrid

Technically both GMO and hybrid seeds are genetically manipulated. The hybrids are changed through breeding and hand pollination, while the GMO seed requires modification through genetic engineering. Either way, the parent plants have been changed through human intervention to produce better outcomes and resistance to certain stresses.

Differences Between Hybrid and Heirloom

Breeding is the main difference between hybrid vs heirloom. Heirloom plants are the result of natural selection, while hybrid plants are selected by humans. Heirloom seeds come true from the parent plant, provided they were pollinated by another of the same plant. The seeds may be saved from year to year. Hybrid seeds cannot be saved because the seed will usually revert to the grandparent plant’s traits.

Which Is Best: Heirloom, Hybrid, or GMO?

It is always the consumer’s choice as to which seed and food to purchase. Dedicated seed savers will likely have only heirloom seed, while those of us who buy new seed annually are getting hybrid selections.

You may see non-GMO labels on seed packets. While this is technically true, GMO seeds are not readily available to home gardeners. This is a marketing ploy, and no matter the seed you're buying, you are almost certainly getting non-GMO.

Heirloom Pros & Cons


  • Open pollinated
  • Completely natural
  • A piece of history
  • May be saved
  • Proven by time
  • May be organic


  • May be more susceptible to disease and insects
  • Open pollination can lead to unusual fruits
  • Less tolerant of weather extremes
  • Produce less

Hybrid Pros & Cons


  • Improved vigor
  • May be more productive
  • Adaptable to environmental stresses
  • Last longer than heirloom seed
  • New selections consistently


  • Seed cannot be saved
  • Flavor is not as good as heirloom
  • Expensive to produce

GMO Pros & Cons


  • Enhanced production
  • Resistance to pesticides
  • Reduces tilling
  • Extensively tested and regulated
  • May be drought resistant
  • Most grow and produce faster than their counterparts


  • Possible toxicity and health concerns
  • Environmental changes
  • Weeds gaining resistance
  • Ecosystem changes due to interactions with the plant traits
Bonnie L. Grant

Bonnie Grant is a professional landscaper with a Certification in Urban Gardening. She has been gardening and writing for 15 years. A former professional chef, she has a passion for edible landscaping.