Is Walmart Watermelon GMO? Separating Fact from Fiction

January 13, 2026 •

4 min read

According to the Watermelon Board, no commercially available watermelon in the United States—including those sold at Walmart—is the product of genetic modification. The misconception around seedless varieties is common, but the reality is a scientific process of hybridization that has existed for decades.

Quick Summary

Watermelons available at Walmart are not genetically modified organisms (GMOs). Seedless versions are created through crossbreeding techniques, a non-GMO process where a plant with 44 chromosomes is crossed with a standard plant possessing 22 chromosomes, resulting in a sterile, seedless fruit.

Key Points

No GMO Watermelons: There are no commercially available, genetically modified watermelons on the market, including those sold at Walmart.
Hybrid, Not GMO: Seedless watermelons are a hybrid created through cross-breeding, a different process than genetic engineering.
The Chromosome Process: Seedless watermelons are produced by crossing a standard 22-chromosome plant with a 44-chromosome plant, resulting in a sterile 33-chromosome fruit.
USDA Organic Is Non-GMO: For definite non-GMO status, look for the USDA Organic label, which prohibits the use of GMOs.
Non-GMO Project Verification: The Non-GMO Project Verified label is another reliable indicator of a product's non-GMO status.
No Special Injections: Watermelons are not injected with anything to make them grow faster or to manipulate their seeds.

The Verdict: No GMO Watermelons at Walmart

For consumers concerned about genetically modified organisms (GMOs), the good news is that watermelons, both seeded and seedless, are not genetically engineered. This holds true for the watermelons you find in Walmart's produce section, just as it does for those from any other major grocery retailer in the U.S. The confusion largely stems from the prevalence of seedless varieties, which many people mistakenly associate with genetic engineering. The truth, however, lies in a traditional horticultural practice known as hybridization, or cross-breeding, which has been used for generations to create new plant varieties with desirable traits.

How Seedless Watermelons Are Really Made

Seedless watermelons are not an unnatural creation of a biotech lab. Instead, they are the result of a deliberate, non-GMO cross between two different types of watermelon plants. The process works like this:

Step 1: Create the tetraploid parent. A standard diploid watermelon plant has 22 chromosomes. In a controlled, laboratory setting, seeds from this plant are treated with a naturally derived chemical called colchicine. This treatment doubles the chromosome number, creating a new, larger tetraploid plant with 44 chromosomes. This is still not a GMO, as no foreign genes are inserted.
Step 2: Cross-pollinate. The pollen from a standard, 22-chromosome diploid plant is used to pollinate the flower of the 44-chromosome tetraploid plant.
Step 3: Harvest the triploid seeds. The resulting fruit produces seeds that have 33 chromosomes, making them sterile and incapable of producing mature, fertile seeds. These are the seeds for the seedless watermelon.
Step 4: Grow the seedless fruit. The triploid seeds are then planted to grow the seedless watermelons sold in stores. The tiny, white seed-like structures inside are not viable seeds but are soft, edible seed coats.

This process is comparable to breeding a horse and a donkey to produce a sterile mule, a reproductive dead-end but a useful hybrid nonetheless. It is entirely different from the process of inserting genes from one organism into another to create a GMO.

Understanding Hybridization vs. Genetic Engineering

To further clarify the difference, it is helpful to compare the techniques side-by-side. Both aim to produce new plant varieties, but the methodology is fundamentally different.


Feature	Hybridization (Traditional Cross-Breeding)	Genetic Engineering (Biotechnology)
Method	Breeding two different parent plants through cross-pollination.	Inserting specific, isolated genes from one organism into another using molecular tools.
Genetic Manipulation	Combines the entire genetic makeup of two parents.	Targets and modifies specific genes, sometimes from completely unrelated species.
Natural Process	Mimics natural reproduction, albeit with human direction.	Uses technology to bypass natural reproductive barriers between species.
Result	New varieties through selection of traits already present in parent lines.	Organisms with new or enhanced traits from the inserted genes.
Legal Definition	Not classified as a GMO.	Classified as a bioengineered (BE) food under U.S. law.

The Source of Walmart's Produce

Walmart sources its produce from a vast network of suppliers, which can vary by season and location. Many of its growers, however, use standard conventional and organic farming methods. Even if a watermelon comes from a supplier who uses genetically modified crops for other products (like corn or soybeans), the watermelon itself is not a GMO. Furthermore, Walmart's purchasing power allows it to form direct relationships with many growers and distributors to ensure a consistent and reliable supply chain. Regardless of the supplier, every watermelon sold is subject to the same scientific reality: there are no GMO versions available on the market.

Identifying Non-GMO Produce

For any produce, not just watermelons, consumers can look for specific labels. While the absence of a "bioengineered" label does not guarantee a product is non-GMO, certain labels provide clarity.

USDA Organic: This certification is a reliable indicator that the food is non-GMO. By law, USDA organic products cannot be produced using genetic engineering.
Non-GMO Project Verified: This label, featuring a butterfly, signifies that the product has gone through a rigorous, independent verification process to ensure no GMOs were used.
PLU Codes: Some people look at the Price Look-Up (PLU) code on fruit stickers. A five-digit code beginning with '9' indicates organic. Historically, a code beginning with '8' signified GMO, but this is no longer a reliable marker as the system is voluntary and the '8' prefix has been repurposed.

Conclusion

The idea that Walmart sells GMO watermelons is a persistent misconception. The seedless watermelons commonly found in stores are the result of traditional, non-GMO cross-breeding techniques that create a sterile fruit. This process has been understood and practiced for over 70 years and is not to be confused with modern genetic engineering. Consumers can enjoy the sweet taste of summer knowing that the watermelons they buy are not genetically modified and are subject to stringent safety standards.

Find more information about the science of food on the National Watermelon Association website.

Frequently Asked Questions

No, most seedless fruits, including seedless watermelons, are not GMOs. They are often created through hybridization or other traditional breeding methods that manipulate chromosome numbers or prevent pollination.

Yes, there is a significant difference. A hybrid is created through cross-pollination, combining the genetic material of two parent plants. A GMO is created by using biotechnology to insert specific, isolated genes from one organism into another, a process that does not occur in nature.

You can be certain because there are no genetically modified watermelons on the market. The varieties are developed through traditional breeding. If you prefer, you can also purchase organic watermelons, which are certified non-GMO.

No, the different colored watermelons, like yellow or orange, are also not GMOs. These varieties have been cultivated through natural crossbreeding techniques and are a result of naturally occurring variations in compounds like lycopene.

Seedless watermelons generally have a similar taste and nutritional profile to seeded varieties. The red color indicates the presence of lycopene, an antioxidant that offers health benefits, regardless of seeds.

Yes, the process is considered safe. The colchicine used to create the tetraploid parent plant is a naturally derived chemical, and the final fruit produced is sterile, not genetically engineered.

This is a common misconception often linked to the confusion surrounding seedless fruits. The absence of seeds, combined with a general distrust of modern food production, leads some to incorrectly assume genetic engineering is involved.