What Are GMOs? What To Know

Updated: Aug. 25, 2023

Soon gardeners might have to decide whether or not to go GMO. Here's what you need to know to make an informed decision.

Mentioning the acronym GMO (Genetically Modified Organisms) can quickly polarize a casual conversation. People who have heard of genetically modified foods tend to have strong thoughts on the matter. And that’s not a bad thing.

It’s important to be aware of GMOs, because love ’em or hate ’em, an estimated 80% of processed foods in our grocery stores, like cereals and pastas, contain them.

When it comes to growing your own food, GMOs have mostly been a non-issue, since those seeds are only available to farmers. But that is changing. Last year the U.S. Department of Agriculture (USDA) approved a genetically modified purple tomato, and its seeds will be available to home gardeners.

It’s likely the beginning of a trend that will escalate over the next five years, says Fred Gould, co-director of the Genetic Engineering and Society Center at North Carolina State University.

“There are companies that are trying to produce things using genetic engineering that maybe a gardener would want,” he says. (Think pit-less cherries and pathogen-resistant tomatoes.) “So as a gardener,” he says, “you have to decide.”

What Are GMOs?

GMOs — aka genetically engineered organisms — are any plant, animal or microorganism whose DNA has been scientifically altered.

This differs from traditional cross-breeding to make hybrid plants because it doesn’t involve natural evolution or cross-pollination. Instead, GMOs are the result of taking genetic material from one organism and inserting it into another. It can also feature gene editing within a single plant’s own DNA.

Currently, GMOs are used primarily in industrial and commercial agriculture. More than 90% of U.S. corn, soybean and cotton crops are GMO. Other crops in the U.S. with GMO varieties available include canola, papaya, sugar beets, alfalfa, potato, apple, squash, rice and pink pineapple.

The first GMO seeds hit the market in 1996. A lot of those crops feed cattle. According to the Food and Drug Administration (FDA), more than 95% of animals used for meat and dairy in the U.S. eat GMO crops. Otherwise, they mostly end up in our homes through processed food containing corn, soy, canola, and others with corn syrup and sugar beets.

What are the Pros of GMOs?

It varies per crop type, but GMO varieties have been modified to give plants these traits:

  • Higher yield;
  • Enhanced nutrition (rice);
  • Longer shelf life;
  • Better taste;
  • Resilience to environmental concerns (drought tolerance);
  • Resistance to herbicides, like Roundup Ready soybeans;
  • Resistance to certain pests and viruses (corn, cotton, papaya, squash).

A major National Academy of Sciences report concluded eating GMO foods is safe, says Gould, the chair of that report. “If you even throw out all of the industry [sponsored research],” he says, “the answer has been that plenty of tests have been done and the current corn, soybean and cotton GMOs are not found to have any measurable health effects.”

But while the FDA, USDA and Environmental Protection Agency (EPA) regulate the safety of GMOs for human and animal consumption, they largely do not take into consideration many of the environmental and societal consequences of the crops.

What are the Cons of GMOs?

Because they are novel organisms present in our food supply for less than 30 years, many people question their potentially negative effects on human health and ecosystems. While GMO crops are widespread in the U.S. and Asia, at least two dozen countries — 16 in the European Union — have banned their cultivation.

Julia Ranney, from the Center for Food Safety, says, “Unfortunately, from our perspective at CFS, the potential GMO pros present as claims as opposed to scientifically proven truths. The cons are numerous. GMOs can pose serious risks to farmers, human health, domesticated animals, wildlife and the environment.”

Biodiversity damage

More than 80% of GMO crops are herbicide-tolerant, meaning that farmers can spray their fields with certain weedkillers without damaging them.

“It has resulted in a 15-fold increase in the application of weedkillers,” the Non-GMO Project, which certifies GMO-free foods, said in a statement to Family Handyman. That erodes ecosystems by killing beneficial insects and plants like milkweed, leading to a steep decline in monarch butterflies.

Impact on farmers

Non-GMO farmers suffer financially when GMO crops or associated chemicals contaminate their fields. Not only can weedkillers kill their crops, cross-pollination means they can also no longer sell them to non-GMO and organic markets. And Ranney says sometimes GMO companies with seed patents accuse farmers of “stealing their property.”

Also, Ranney says, “These companies can entrench farmers in systems of production that require them to buy the seeds every year and the related fertilizers/pesticides. It’s a very expensive venture that can displace traditional livelihoods and indebt farmers when the promises of increased yields fail.”

Food security

With three corporations owning 60% of the world’s seed, the biodiversity of crops farmers plant has diminished. This less-diverse food supply threatens food security in the face of a changing climate, unstable weather patterns and emerging crop diseases.

“There are also cultural risks for species that are central to the traditions of certain cultural groups,” according to the Non-GMO Project statement. “For example, corn is a very important traditional resource in Mexico so GMO contamination is a serious concern.”

GMOs and Your Garden

It’s unlikely you have GMO vegetables in your garden, or that any of the seeds and seedlings you’ll buy this spring will be genetically modified.

“The only way you could get GMOs in your garden is if you live very close to a commercial farm that grows genetically engineered corn, and the pollen from that corn gets on your corn,” says Gould.

Three GMO flowers are currently deregulated by the USDA: Petunia- A1-DFR, Rose- IFD-52401-4, IFD-52901-9 and Suntory Flowers Limited Chrysanthemum.

But mostly, GMOs in your garden are a question for the future. For this year, the more pressing questions to ask when buying plants and seed are:

“A lot of gardeners who grow their own food are pretty conscientious about their seed sources,” says Heather Andrews, the Thoughtful Gardener. “The reason they’re growing their food is so they can control the process.”