If you’ve ever explored a vegetable seed rack, you’ve probably noticed an array of choices. However, there are three basic types of seeds:

Hybrid varieties have been bred for particular traits such as growth pattern or disease resistance. They have been hand-pollinated, and are patented, often sterile, genetically identical within food types, and sold through both multinational and small seed companies. F1, or first generation hybrids are true to their variety only in the first generation and are not reliably reproducible from their own seeds.

A second kind of seeds is genetically modified (GM); the DNA of the plant has been changed in a laboratory by the addition of DNA from another organism (which may not even be another plant). GM seeds are not commonly available to home gardeners, but are widely used in commercial agriculture for crops such as corn, soy, rice, potatoes, and more.

Heirloom seeds, sometimes referred to as open-pollinated seeds, are genetically diverse and have been handed down from generation to generation. Typically, heirlooms have been developed over time for optimal response to their local climate and soil by virtue of being hand-selected for particular traits. This selection may have included plants that are resistant to local pests, diseases, and extremes of weather. The diversity of heirloom plants is considered by many researchers and gardeners alike as critical to maintaining the genetic diversity of the world’s food crops. Today’s gardeners can continue this tradition by saving seeds from their favorite individual plants to preserve those special traits.

If a seed is labeled as organic, the contents were produced without artificial fertilizers or pesticides and are not chemically treated. Organic seeds may be available in both hybrid and heirloom varieties.

Growing heirlooms gives gardeners a role in maintaining the biodiversity of our planet. While hybrids have been bred to resist particular diseases, there are occasionally threats that could possibly wipe out entire crops when a new disease arrives, due to the lack of diversity in varieties commonly planted. Every time an heirloom seed is planted, that seed stock is regenerated, maintaining that gene pool with its own taste, growth habits, and resistance to disease and insect pests. If you’re interested in saving seeds from flowers or vegetables you would like to plant again next year, you can select seeds from your favorite plants to encourage particular traits, such as early production, a particular size, or outstanding flavor.

Heirloom seeds are available both locally and online; you can also save money each year by saving seeds from your plants and exchanging seeds or starter plants with your neighbors. (refer to the seed saving article in the Gardening section).