The terms "hybrid," "heirloom," and "genetically modified (GMO)" get tossed about a lot today and nowhere more so than in the garden—specifically, the vegetable garden. In plants, the terms refer to how the plants are reproduced: whether by simple seed saving, by cross-pollinating two different species, or by introducing foreign genes. None of these methods are easily labeled good or bad and you won't find much agreement on which is the best, either. Heirlooms are plants that have stood the test of time, hybrids are often more disease-resistant or higher-yielding, and GMOs although still the subject of many studies, can be lifesavers. Each has its pros and cons.
What Type of Vegetable Seed Should You Choose?
How can you be sure that the hybrid vegetable seeds you grow aren't genetically modified and bad for you? Would you be better off sticking to heirloom vegetables or could they be modified, too? Here's a breakdown of what you are getting from each type of seed.
Heirloom vegetables are not a special species of plants. The term heirloom vegetable is used to describe any type of vegetable seed that has been saved and grown for a period of years and is passed down by the gardener that preserved it. It has a provenance, of sorts. To be capable of being saved, all heirloom seed must be open-pollinated, so that it will grow true to seed.
Open-pollinated—or OP—plants are simply varieties that are capable of producing seeds that will produce seedlings just like the parent plant. Hybrid plants do not do this.
Plant breeders crossbreed compatible types of plants in an effort to create a plant with the best features of both parents. These are called hybrids and many of the modern plants are the results of these crosses.
While plants can cross-pollinate in nature and hybrids repeatedly selected and grown may eventually stabilize and become open-pollinated, most hybrid seeds are relatively new crosses and seed from these hybrids will not produce plants with identical qualities.
For example, each year new hybrid tomato varieties are offered. You may see them labeled as hybrids or F1 also known as the first filial generation (first-generation hybrid) or F2 also known as the second filial generation. These may eventually stabilize, but for the moment a tomato such as the popular 'Early Girl' does not produce seeds that reliably have the features you expect in an 'Early Girl' tomato. Seed from hybridized plants tends to revert to the qualities of the parents, so tomatoes grown from seeds saved from your 'Early Girl' tomatoes might still be tasty, but not so early.
Anyone can select and eventually stabilize their own seed or even hybridize new plants, but the plant and seed companies have recently begun patenting their crosses so that only have the right to reproduce the hybrids they've developed.
Genetically Modified Plants
Hybrids should not be confused with genetically modified organisms—or GMOs—which can be any plant, animal, or microorganism that has been genetically altered using molecular genetics techniques such as gene cloning and protein engineering. Plants like corn that has the pesticide Bt engineered into its genetic makeup to make it resistant to certain pests are GMO crops. Bt is a natural pesticide, but it would never naturally find its way into corn seed.
You probably are not too keen on infusing your food with pesticides, and the overuse of a pesticide often results in the targeted pest becoming resistant to it. These types of concerns have given GMOs a terrible reputation. However, there are times when GMOs have arguably been quite positive in their impact—such as the high-yield, disease-resistant dwarf wheat introduced by Norman Ernest Borlaug, which helped increase the food supplies in India and Pakistan.