Heirlooms and Hybrids

We’ve all heard some seeds or plants described as heirlooms and others hybrids, but what do those terms really mean?

Both hybrids and heirlooms come about through naturally occurring cross-pollination, as opposed to genetically modified organisms (GMOs), which are created in a lab using altered DNA strands.

Pre-industrial agriculture

Before agriculture became an industry, people grow a wider variety of plants for food. That biodiversity helped offset inclement weather, diseases and pests, and other threats to a failed crop and the resulting starvation. Corporate agriculture, on the other hand, feeds countless millions by generating a smaller variety of uniform plants that consistently grow at specific rates, that can be sprayed with a variety of pesticides, herbicides, and fungicides, ship well, and store well. As many of you know, taste and texture often suffer s a result. ​

Heirloom tomatoes (hedwigmaria) Pixabay

Pros & cons of heirlooms

Heirloom seeds are those that have been handed down, person to person, in a specific geographical region, for a very long time. Also, heirlooms are open-pollinated, which means pollination occurs naturally, by wind, birds, animals, and insects, and not by human efforts. Heirloom varieties are at least 50 years old (some say 100 years), and many of them have been grown consistently, in the same locale, since before WWII. These plants have evolved to take advantage of local microclimates and beneficial insects. Heirloom seeds are hand selected by gardeners from the very best plants each growing season.  Many heirloom plants do not have the uniformity or long term storage capabilities of hybrids, but growers (myself included) claim that the flavor is significantly better. Heirloom crops have more variety in size and shape than hybrids, but they always grow true to their parent plants. Heirlooms are more genetically diverse, making them more durable as a species, and less susceptible to local pests and diseases. Heirloom offspring are fertile and can reproduce.

Pros & cons of hybrids

Hybrid plants are intentionally created by cross-pollinating different varieties of a species. The intention of hybridization is to take advantage of the best characteristics of each parent plant, creating what is known as hybrid vigor (heterosis). This vigor only lasts for one generation. Hybrid seeds do not grow true to their parents and they lack vigor and genetic diversity. This lack of diversity is what caused the Irish Potato Famine of the 1840s. If all the plants are identical, they are equally susceptible to pests and diseases. A single threat can be devastating.

Creating a hybrid that grows “true” to the desired characteristics takes years of diligent effort. Plants are often pollinated by hand or grown in greenhouses or pollination bags that block contamination from outside pollen to ensure that pollination only occurs between the desired plants. The majority of the fruits and vegetables you see in grocery stores are hybrids. Harvests are very consistent in size and shape. Hybridization is done for many specific characteristics:

• improved disease resistance
• easier growing
• early maturity
• better flavor
• bigger size
• longer storage capabilities

When shopping for plants and seeds, one way to know if it is a hybrid is to look at the Latin name. If you see the letter “x” between words in the name, it is a hybrid. For example:

Raspberry (Rubus idaeus) crossed with blackberry (Rubus ursinus)
  creates Loganberry (Rubus x loganobaccus)

*Check labels for the letters V, F, N, T or A. These symbols indicate a resistance to verticillium wilt, fusarium wilt, nematodes, tobacco mosaic virus or alternaria stem canker, respectively.

Understanding the difference between heirlooms and hybrids can help you make the right choice if you want to collect viable seeds from your harvest for next year’s planting.