There are a lot of terms out there describing seeds, or rather, the parentage and genetic lines of seeds. Heirloom, open-pollinated, hybrid, F1, even F2, and GMO. All those terms have at least something to do with the reproduction and parental lineage of the plant variety in question. Understanding the meanings of the various descriptions is important when selecting varieties, and it also helps if you want to save seeds later. 

Which seeds are best for you? What do those terms mean? Here’s a guide to help explain it all.

What are Hybrid and F1 varieties?

In gardening, hybrid is a term for a plant variety created by a controlled cross between two distinct but related parent lines (of plants). If you took a little artist's paintbrush and pollinated the flowers of one squash that grew well in your garden with another whose taste you really liked, the resulting seeds, or more specifically the plants that grow from them next year, would be hybrids. 

Hybrid seeds are normal, perfectly safe, and usually offer advantages in vigor, growth rate, productivity, or even disease resistance. They are not the same as GMOs, which is a common misconception.

Breeding (through pollination) of two different parent plants selected for some desirable trait, like growth rate or flavor, is how many of our favorite varieties have been created. To create hybrids, breeders conduct controlled cross-pollination. It means they take measures to prevent natural pollination and manually transfer pollination from one plant to another to ensure only the correct parents (the ones we wish to cross) will contribute their genes.

In catalogs or online, you may see a hybrid variety referred to as an F1, also written as F(1). This designation is a specific hybrid, the first-generation offspring of two parent plants. So, in our example above with the brush and the squash plants, those seeds (representing the plants they will grow into) are F1 hybrids. 

It’s a fun bit of information, but for most of us, it isn’t that important. Nearly all garden seeds labeled as hybrid are F1 (first-generation) hybrids. While there are other designations, like F2 and even F3, they aren’t common. 

The important thing to know about plants labeled as hybrids or F1 is that saving seeds from these plants will likely result in offspring plants that are not quite the same as the original hybrid. You may have noticed this if you’ve had volunteer tomatoes pop up in your garden the next spring. Unless you planted an open-pollinated variety, the volunteer plants are usually slightly different in shape and structure, growth rate, and fruit. 

Because of this characteristic of not reproducing true to variety, gardeners who save seeds usually don’t do so from hybrids. If you’re looking to save seeds, you’ll want to choose an open-pollinated variety.

Heirloom and Open-pollinated varieties

Shop seed catalogs, and you’ll see some varieties described as heirloom. Others are listed as open-pollinated. But aren’t all seeds pollinated in the open? If the flowers weren't pollinated, the seeds would be sterile or wouldn’t form.  

Open-pollinated, when referring to seeds or plant varieties, means that the next generation of that plant will be true to the physical form and characteristics of the parents when they are pollinated with the same variety. 

With all environmental factors held equal, an open-pollinated tomato would reproduce true, and next year’s plants and fruit would look like those from this year. Think of them as a stable reproducing population, say of tomatoes, as long as another tomato variety doesn’t sneak in some pollen. If you grow two tomato varieties, or your neighbor grows a different tomato over the fence, the bees and other pollinators may introduce some cross pollination on you. 

Just as we are a mix of our parents' DNA, so are seeds. The specific DNA unique to an organism is called the genotype. The way a plant actually looks is its phenotype. 

• Genotype is the genetic sequence or genes of an individual organism, in this case, a plant. It is this set of genetic material inherited from the parents that determines the traits of the plant. 

• Phenotype is how genetic traits are expressed in response to environmental factors. For example, a particular variety of corn may have genes programming it to be a seven-foot-tall plant, but due to poor soil fertility or lack of sunshine, it may only reach four feet tall. 

So what is cross-pollination? In light of the above, we can now see that cross-pollination is the exchange of genetic material, i.e., pollen, from two different plant varieties. For example, between San Marzano and Jersey Devil tomatoes. While some crosses yield stable new varieties over time that may qualify as open-pollinated, many do not and remain hybrids, available only by breeding new seeds every year. Hybrids have genotypes that won’t reliably recur from saved seed, so seed producers recreate the cross each time.

What’s an heirloom variety?

Heirloom varieties are open-pollinated, but have a long history. They could be considered old school, antique, or historical varieties. While no specific standard exists, most heirloom varieties have been constantly grown since the early part of the last century or earlier. These seeds have been grown, saved, and passed down for decades because they are favorites due to their colors, shapes, flavors, or even historical significance.

Basically, all heirloom varieties are open-pollinated, but not all open-pollinated varieties are heirlooms–yet. Many of our modern hybrid vegetables were bred for increased production and disease resistance, but purists claim that if you want the best flavor, return to the heirlooms that were kept around because they were people’s favorites years ago. If you want to experiment with some fun flavors, shapes, and colors, check out some heirloom plant varieties.

A Note About Corn

For most plants, we eat their fruits, and not the seeds. We eat a carrot root, a tomato fruit, or a zucchini. But for sweet corn, we eat the seeds. Cross-pollination won’t affect the characteristics of this year’s fruit. After all, the fruits are already forming before the seeds mature. But it will affect the seeds. It’s the reason why planting your sweet corn near other types of corn, assuming they shed pollen at the same time, can yield strange results, like tough, unsweet sweet corn.

What is a GMO seed, anyway?

We have all heard about GMO seeds and crops, but there is a lot of misinformation about what they are. Some folks think every hybrid is a GMO seed, which is not true. So what’s the actual meaning of GMO?

GMO stands for genetically modified organisms. These seeds and plants are not created by cross-pollination, selective breeding, or open pollination. Instead, they are created by genetic engineering in a lab, using molecular techniques such as genome editing to insert, remove, or rearrange specific DNA sequences. The result is a new combination that would not occur through normal plant reproduction. Inserting a piece of bacterial DNA into the DNA of field corn to improve resistance to herbicides is an example of a GMO.

Hybrids, even if the pollination was performed by a person in a lab wearing a white coat, are the result of normal and natural pollination processes. Humans just helped with pollination or were selective of the specific parent plants used. At Seeds n’ Such, we only sell non-GMO varieties. What you will find is a wide selection of hybrids, open-pollinated, and heirloom seeds!