Hybrids have been around for hundreds or years, the first research done by Gregor Mendel, an Augustinian monk in the 19th century who taught natural science to high school children and researched the traits of sweet peas “for the fun of it.” His work became the foundation of modern genetics, and many of his terms we use today.
Like Mendel, commercial breeders cross two different parent varieties to create an “F1 hybrid”, the first filial generation to demonstrate a new uniform seed variety with specific characteristics of both parents. To take tomatoes as an example, a variety with great disease resistance could be crossed with a variety with an unusual orange color to make an F1 hybrid that exhibits the best of both parents.
The unique characteristics of an F1 hybrid are uniform only in the first generation of seed, so seed saved from F1 plants will not grow true if planted and may exhibit many different traits in the second generation. To guarantee consistent F1 hybrid plants breeders must repeat the original cross each season using controlled hand pollination. Many commercially available tomato seeds such as ‘Early Girl’ and ‘San Remo’ are F1 hybrids.
All heirloom varieties are ‘open-pollinated’ -- although not all open-pollinated seeds are heirlooms. In open pollination the seeds are the result of either natural or human selection for particular characteristics which are then reselected in every crop. The seed is pollinated by wind or bees, not human hands, and are kept true through selection and isolation.
The definition of “heirloom” is rather vague, it usually means a variety that is around 50 years old and that is no longer available in the commercial seed trade and that has been selected and preserved in a particular area.
As a home gardener, if I buy heirloom ‘Green Zebra’ tomatoes from a local farmers market and plant the seed from the most delicious fruit in my plot, and then each year carefully select the seeds from the earliest ripening, best-tasting plants in my PA climate zone and soil type I would develop a locally adapted strain of ‘Green Zebra’ that is different from a ‘Green Zebra’ grown in Boston or Washington.
If you are growing an unknown, open-pollinated tomato variety that has been handed down to you through five or six generations from a local friend, it would be considered an heirloom variety. Obviously there is something special about this plant that has caused local gardeners to select and save the seed, heirloom tomatoes often have fabulous flavor and texture or unusual colors but can lack the disease resistance, early maturity or uniform shape that makes them commercially viable.
When selecting varieties it’s important to choose the right seed for your needs. Hybrids can have great flavor, and can offer better disease resistance, increased productivity and a broader maturity range than heirlooms.
If you’re short of space, there are F1 hybrid tomatoes selected to grow as a short bush instead of a sprawling vine and that have a more concentrated harvest than heirlooms. Aesthetically I love the rainbow colors and fabulous shapes of heirloom tomatoes and so when space permits I am happy to sacrifice the hybrids more plentiful and reliable harvest for the misshapen yellow, orange, pink, purple and striped orbs of the heirlooms.
However, I also love the colors of the hybrid ‘Bright Lights’ Swiss chard, the rich dark green crumpled leaves are a wonderful alternative to spinach and the stems are all shades of yellow, gold, orange, pink, violet and striped and are delicious to eat as well as beautiful to look at. I’ve had miserable luck growing heirloom broccoli and would only plant a hybrid variety that is more resistant to pests and diseases.
Like most things in life I think diversity is key and those who are narrow minded in their choices lose out. Enjoy the best of the hybrids with the best of the heirlooms and keep notes so you remember what varieties thrived in your environment and what failed. Gardening is an endless experiment, with nature as the controlling hand.
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