There are many different categories of seeds—heirloom seeds, hybrid seeds, open-pollinated seeds, GMO seeds, F1 hybrid seeds—but what’s the difference between them all? Which ones are the best seeds for home gardeners to grow? This post will cover these topics and more.
You may have heard a fellow gardener say, “Oh, I only grow heirloom seeds in my garden and never hybrid because they just don’t taste as good.” Or you may have heard the opposite. Maybe someone refuses to grow heirloom tomatoes, for example, because “they’re just too finicky and they don’t grow as well as hybrid seeds.”
When I first started gardening from seed, those are exactly the kinds of comments I heard from more experienced gardeners and it made me very confused.
Who was right and who was wrong? Are heirlooms better than hybrid? Why or why not?
So, I want to share what I’ve learned over my years of gardening about heirloom, hybrid, and GMO seeds and help to demystify these terms. We’ll go through the key differences between heirloom and hybrid seeds and everything in between, including non-GMO and GMO seeds, so gardeners like you and me can make the right choice about the type of seed to grow in their gardens.
Key Characteristics of These Different Types of Seeds
The key characteristics of heirloom seeds include the following:
- genetic stability (seeds consistently produce plants with the same characteristics as the mother plant)
- saved for 50+ year
- passed down within a family or community, often adapted to a certain area
- seeds often carefully selected to preserve desired characteristics like color or flavor
- open-pollinated (pollinated by insects, birds, or wind)
Hybrid seeds have these characteristics:
- controlled pollination in which a human intentionally crosses two different plant varieties or species to breed a desired trait
- generally has higher vigor, growth, and yields
- consistent plant traits (size, color, or shape)
- genetically unstable (seeds saved from a hybrid plant will not grow true-to-type, so new seed must be bought every year)
- not open-pollinated (must be intentionally crossed by humans)
GMO (Genetically Modified Organism) seeds are not typically available for home gardeners to purchase, but here’s the key characteristics nonetheless:
- genetically modified through the insertion of specific genes directly into the DNA of the seed (often to resist certain pests, diseases, or herbicides)
- created in a lab through scientific means (versus natural means of transferring pollen from flower to flower whether by humans or others)
- expensive to buy, typically only grown by commercial farmers growing on a large scale
What Are Heirloom Seeds?
Heirloom seeds are seeds that have been cultivated and passed down through generations, typically for 50 years or more. Maybe great-grandma brought special tomato seeds from Italy that her family always grew, and now her family exclusively grows and saves seed from that tomato in America.
Just like families pass down heirloom jewelry or furniture, seeds can be passed down to the next generation of gardeners.
When properly stored, seeds can really last a long time. I wrote a post about seed expiration dates and seed storage which you can read if you’re interested.
Heirloom seeds have been saved year after year, often selected by gardeners to preserve and perpetuate certain characteristics, like color, flavor, size, yield, disease or pest-resistance, or earliness of the crop.
Why Heirloom Seeds Are Special
While all heirloom seeds are open-pollinated, not all open-pollinated seeds are considered heirloom. This is where the distinction of time comes in.
To be able to call something an “heirloom seed,” it must have been open-pollinated and stewarded for 50+ years. These kinds of seeds are special because they have cultural significance and a story behind them.
Long ago, gardeners learned that saving seeds from their biggest tomato, or their earliest pepper, or from a specially shaped squash would keep those characteristics going to the next generation of plants. And if they kept saving seeds from that generation’s biggest tomato, earliest pepper, or specially shaped squash, that next generation of plants would be even more likely to have the previous generation’s characteristics.
When this goes on for years and years, the genetics of those special varieties stabilize and seeds reliably produce a plant with those special characteristics.
In addition, those seeds adapt to the growing conditions of the area they are grown in. So they not only have the special characteristics that a family has saved over generations, but over time, they also grow best in the climate and care of the family that has stewarded them.
This is why some gardeners value heirloom varieties grown in their region so much. The plants have adapted to that climate and have been selected for years to have certain characteristics. Often vegetable seeds were saved for best flavor, which is why so many gardeners exclusively grow heirloom vegetable seeds. They taste the best!
But Hybrid Seeds Are Good, Too
If you think about it, heirloom seeds were once hybrid seeds, too. At some point, an insect or human or something crossed the pollen from one variety of plant with another variety. Then the resulting seeds from that crossing were grown out and continually saved and grown.
Hybrid seeds are not at all bad. The term “hybrid” simply means that a person intentionally pollinated one plant variety with another plant variety to get a certain plant trait to appear. Hybrid seeds are also known as F1 hybrids or F1 generation seeds. The number signifies the generation grown since the original crossing of two plant varieties. If the F1 seed is grown out, crossed with itself, saved, and replanted, it would be an F2 hybrid.
These desired traits are often very practical for growers: higher yield, disease resistance, drought resistance, etc.
In the first year that these newly crossed seeds are grown, they have what’s known as “hybrid vigor” or heterosis. This means that the plant babies are bigger, more productive, and generally stronger than their plant parents.
This is why hybrid seeds are also valuable for home gardeners.
Why Some Gardeners Refuse to Grow Hybrids
You may think, hybrid seeds sound great! Let’s all only grow hybrid seeds.
Well, there are some gardeners who would disagree.
For one thing, hybrid seeds will not produce offspring that are true to type. If you plant a hybrid seed, grow it out, then save the seed and replant it, chances of getting a plant with the same characteristics as the original hybrid seed are very low. In fact, they will probably be more like one of the original hybrid seed’s plant parents than like the mother plant.
Because they have to be crossed intentionally, hybrid seeds cost more than heirloom seeds.
Also, if we all exclusively grow hybrids, many heirloom seeds would be lost forever. Hybrid seeds threaten the genetic diversity of our world when they are exclusively used or overused.
Many gardeners place a higher value on the cultural significance and connection to our agricultural ancestors that comes with growing heirloom seeds.
If you also value heirloom seed preservation, check out Seed Savers Exchange. They grow, steward, and share open-pollinated and heirloom seeds of all kinds and encourage gardeners to do the same.
Should We Grow Heirloom Seeds or Hybrid Seeds?
I think both heirloom and hybrid seeds are great for home gardeners to grow. Why should we have to choose to exclusively grow one or the other?
For example, I enjoy growing heirloom tomatoes for their incredible flavor, but I only grow hybrid zucchini because I struggle with pest pressure so much and I’ve found a hybrid variety that grows against all odds.
It doesn’t have to be just one or the other.
There are advantages and disadvantages to both types of seed. I would encourage you to carefully consider your gardening goals and values before you purchase either kind of seed.
The story and purpose behind growing heirloom seeds does tug at my heart, so I do intentionally try to choose heirloom over hybrid for myself. I also want to save seeds whenever I can, and heirloom and open-pollinated seeds are better for that purpose.
What Will You Choose?
I’m curious to know what type of seed you will choose to grow. Leave a comment below and let us know whether you are growing heirloom, hybrid seed, or both in your garden this year.