Heirloom? Organic? Hybrid? Types of Vegetable Seeds, Explained

Spring is an exciting time for gardeners, especially new ones. Fantastic, colorful displays of seed packets can be found almost everywhere during this season. But choosing seed types can be quite overwhelming, especially if you’re attempting to garden according to specific principles. We’ll help differentiate between options so you can choose the right seeds for your vegetable garden. Here’s an explanation of the common types of seeds available for sale.

Heirloom seeds

Heirloom seeds are open-pollinated seeds that have not be exposed to hybrid breeding. Open-pollination simply means that a plant has been pollinated in natural form: wind, self-pollination, or insects, for instance. The use of these seeds guarantees that gardeners will always reap what they thought they sowed. Heirloom seeds will produce plants with the exact traits of the parents, assuming that they have not been accidentally exposed to cross-pollination. But heirloom seed breeders are careful to control for these conditions.

There is debate over how old seeds must be to be considered “heirloom.” Some claim 50 years, some claim 100 years, and others pinpoint the year in which World War II ended and the modern agricultural industry began: 1945. The majority agree, however, that heirloom seeds cannot utilize genetically modified organisms (GMOs). More on this next. The Clemson University Cooperative Extension tells you more about heirloom vegetables here.

Non-GMO seeds

The terms genetically modified (GM) and genetically engineered (GE) refer to recent advances in technology that allow producers to incorporate desired genes into an organism. For example, companies might add a gene to corn to make it more drought-resistant, which therefore expands the regions in which the crop can be grown.

There is considerable debate about GM products. Groups of consumers and gardeners alike have rallied against GM crops, citing potential contamination issues and the uncertainty of long-term health effects. However, many companies and researchers support GM efforts to solve worldwide problems that contribute to malnutrition, famine, and starvation, such as regional nutritional deficiencies or harsh growing climates.

As you can guess, non-GMO seeds indicate the seeds are free from this type of modification. In fact, only a few GM vegetables are available commercially in the United States today. Currently, any vegetables outside of corn, soybeans, and squash will not contain GMOs.

Want to learn more about GMO? NPR has an interesting article about GMO myths. Scientific American takes on the subject of GMO crops here, and here.

Certified organic seeds

Organic vegetable seeds carry the same meaning as the organic produce sold in a supermarket. These seeds are produced according to organic standards: the use of chemical or synthetic fertilizers is prohibited. The U.S. Department of Agriculture only allows manufacturers to use the “organic” label if they have proven to use only organic methods. This applies to multiple industries: pharmaceuticals, farms, canned goods, and cosmetics, to name a few. This organic certification is appealing to many consumers and gardeners since the USDA regularly inspects certified facilities and enforces strict penalties and fines for noncompliance.

Certain standards apply that producers must fulfill  in order to become accredited organic growers. There is a two-year conversion process in which growers must prepare their land; anything grown within the first year of this period may not be stated as organic, while the second year is considered “in conversion.” It is not until the third year that growers may be permitted to use the organic label.

What may make the program confusing is that the FDA offers three categorizations: 100% organic (which presents no ambiguity), 95% organic (made with 95% organic ingredients), and “made with organic ingredients” (a minimum of 70% organic ingredients with the remaining 30% restricted to non-GMO ingredients). Products that fall under the last category may not use the “certified organic” label on their packaging.

For more information on the USDA’s organic rules and regulations, see their National Organic Program website.

Standard, untreated seeds

Standard vegetable seeds available for purchase at most locations are those that have been produced under non-organic conditions. This includes the use of synthetic fertilizers and pesticides. It is possible the seeds have actually been grown using organic methods, but the grower hasn’t undergone USDA organic certification. Unless marked, they do not contain GMOs, but there is no guarantee that cross-contamination has been avoided.

Treated seeds

As mentioned above, standard seeds might be organic or contain GMOs. Treated seeds receive an additional application of fungicide or other chemicals, sometimes organic, to enhance their properties. Some reasons seeds are treated are to extend growing time, improve crop quality, or protect from disease or pests. The type of treatment used may or may not be considered organic. Packages are labeled “treated” and it is important to check the treatment type if you seek a specific type of vegetable seeds.

Hybrid seeds

Understanding hybrid seeds requires a little refresher from Biology 101. Hybrids are created during a controlled breeding process. The two parent plants will always produce the same offspring when they self-pollinate. Using these two parents, cross-pollination will produce a seed that combines features from both parents. The goal of hybrid breeders is to capture the most valuable traits from both parents and create a superior vegetable plant.

Humans have been cross breeding plants to develop new plant varieties since the beginning of agriculture. A hybrid seed or plant is not the same as a GMO seed or plant. Learn more about the difference between GMO and hybrid plants in this Mother Earth News article.

Texas A&M has a good article that explains why saving seeds for the next season won’t give you the same results.

About.com also gives a good explanation of the difference between heirloom, hybrid and GMO seeds.