About Heirloom Seeds
As you review seed catalogs and seed sites to make selections for your garden, you may be confronted with the following terms:
Knowing the difference among these terms will help you make better-informed seed selections and gardening decisions.
Heirloom / Non-Hybrid / Non-GMO / Open-Pollinated Seeds
Natural “Open Pollination”
Heirloom plants are the result of natural, open-pollination and possess stable traits from one generation to the next.Heirloom plants are distinct from hybrid varieties. Heirloom or “standard” plants are non-GMO, meaning they are not genetically modified. Hybrids are the result of genetic modification. In the world of gardening, this is a critical distinction.
Open-pollinated plants are fairly similar to each other though may not be as uniform as hybrids. Because most heirloom varieties were originally chosen for only one or two specific characteristics, individual plants grown from older heirloom varieties may differ in size, shape, or other traits.
Open-pollinated varieties are usually grown in fields where they self- and cross-pollinate. Wind and insects carry the pollen from one plant to another. Plants that cross-pollinate should be isolated from other plants of different varieties so they will produce seed that is "true to type." Beans, lettuce, peas, and tomatoes are self-pollinating so they are easier to continue year-to-year without having to isolate them from other varieties of plants.
Genetic "drift" can occur over a period of time. Plants that deviate too far from the accepted standard are removed from commercial nursery fields of open-pollinated varieties. Likewise, as a home gardener, you should weed out highly unusual plants if you are trying to preserve an open-pollinated variety. Removal of these rogue plants prevents them from pollinating other plants and producing too much variation.
The Advantage of Heirloom Seeds
The distinct advantage of open-pollinated, heirloom seeds is that the home gardener can, from year-to-year and generation-to-generation, continue heirloom plants by careful seed-saving. Open-pollinated plants provide a larger gene pool for future breeding. Well known, open-pollinated varieties include Kentucky Wonder pole bean, Scarlet Nantes carrot, Black Beauty eggplant, Black Seeded Simpson lettuce, California Wonder pepper, as well as Brandywine and Roma tomatoes.
The Result of “Controlled Pollination” – Genetic Modification
Crossing specific “Parent Plants” produces a genetically modified, hybrid seed (plant) by means of Controlled Pollination.
These hybrid seeds are often called "F1" or "F1 hybrids." The terms "hybrid" and "F1" are strictly defined in the seed industry. When used in seed catalogs and on commercial seed sites, the term “hybrid” does not apply to naturally occurring cross-pollination of plants that happen in the wild.
Some people think of a hybrid as blending two different plants, essentially like crossing a red-flowered plant with a white-flowered plant to get a pink-flowered offspring. Unfortunately, the laws of genetics prevent it from being that simple. Most hybridized plants require the cross breeding of carefully chosen parent plants. The resulting seed will produce plants with very specific characteristics. Hybrids carry a combination of traits from both parent plants.
Creating Hybrids through Genetic Modification (Hand-Pollination)
Based on desirable traits, breeders select specific male and female parent plants. The plants selected to be the female, seed-bearing partner have their pollen-bearing anthers removed. They receive pollen only from those plants selected as their male partners. By controlling the pollination, the resulting offspring will have identifiable genetic characteristics from both parents.
Producing hybrid seed is more time consuming and expensive because the plants must be hand-pollinated. In addition, plant breeders may work for years to find the right combination of desirable traits they are looking for in a plant.
The breeder of an F1 hybrid variety can often be the exclusive source of that variety. Only the breeder knows exactly which two parent plants are needed to produce the seed. Other breeders can try to duplicate a hybrid, but only the first breeder knows the exact combination. Of course, the process of trying to breed new and better hybrid varieties often result in unexpected new varieties.
Not every F1 hybrid is a winner. The All-America Selections program, and other similar trial gardens, test new varieties side-by-side to see what improvements, if any, have taken place in a certain type of flower or vegetable. Before a variety reaches the market, seed companies perform their own trials. Many attempted hybrids end up in the compost pile, never to be seen again.
The additional work required to produce hybrid varieties usually also means higher costs passed on to the gardener. Are hybrid varieties worth the price? Selecting hybrid seeds means you must buy seeds every single year for your garden.
Hybrid varieties do have some advantages such as adaptability to environmental stress and greater uniformity from plant-to-plant. Some varieties produce earlier or higher yields. Many provide some measure of improved disease-resistance which lessens the need for pesticides.
Disadvantages of Genetically Modified Hybrids – Consider the Trade-Offs
There are trade-offs. If you are committed to growing traditional, true-to-type, genetically unmodified plants for your table, be wary of introducing hybrid varieties to the garden. Significant controversy still surrounds genetically engineered seeds as they may present a public health hazard. There has, admittedly, been insufficient long-term testing to determine whether or not genetically engineered seeds are safe for human consumption.
There are also other distinct disadvantages to growing hybrids in your garden. The primary disadvantage of hybrids is that seeds cannot be saved from year-to-year. Seeds saved from hybrid plants usually will not produce the same plant the following year because most varieties are not self-sustaining. Offspring of hybrids usually show an unpredictable mixture of characteristics from the grandparent plants instead of being similar to the parent.
Additionally, many gardeners prefer the taste of heirloom varieties over the taste of hybrids. While taste is somewhat subjective, and many hybrid varieties have gained some measure of popularity, heirloom varieties have vast appeal to gardeners committed to growing and enjoying safe, genetically unmodified plant varieties.
If your personal gardening philosophy embraces “back to nature,” then heirloom, non-hybrid, non-GMO (genetically unmodified) seeds is the only place to begin.
Source: University of Illinois Extension