What’s the Difference Between Heirloom Seeds, Hybrid Seeds, and GMOs?

When you have limited space to grow flowers, fruits, herbs, and vegetables, as most home gardeners do, choosing what to grow each year can be daunting. Adding to the confusion is the choice between heirloom seeds, hybrid seeds, and the pros and cons of each.

What is an heirloom plant?

An heirloom plant has been grown for generations by gardeners and farmers, sometimes for hundreds of years. Heirloom seeds can be saved every year, and the plant can be grown again the following season. To be considered an heirloom variety, the common age of the plant is at least 50 years.

An heirloom plant retains its traits through open pollination, meaning wind, insects, birds, or animals carry the parent plant’s pollen from flower to flower, fertilizing each plant to create the next generation of seeds. The seeds from heirlooms generally “breed true” – you can expect a nearly identical plant from each generation of seeds.

Since heirloom plants are open-pollinated, cross-breeding may occur between varieties, leading to genetic drift. This means that the genes for flavor, sweetness, eating quality, size, shape, or color may shift over time. Eventually, a completely new variety can naturally occur. This is similar to how plant breeders create new, open-pollinated varieties, but they speed up the process.

A benefit of open pollination is it creates a genetically diverse gene pool that allows plants to slowly adapt to local growing conditions. But just because a variety is an heirloom, it doesn’t mean that it’s superior to a hybrid.

Buy on Amazon: Heirloom and Hybrid Garden Seeds

What is a hybrid plant?

A hybrid plant is the result of pollinating one specific variety of a plant with the pollen of another genetically different variety of the same class of plants. For instance, a tomato with a bright red color is intentionally crossed with a variety of tomato that is resistant to late blight to create a bright red tomato with less susceptibility to late blight. Breeders “steer” hybrid plants into trait dominance by cross-breeding with relatively low tech methods, such as hand pollinating each flower.

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 partners. By controlling the pollination, the resulting offspring will have identifiable genetic characteristics from both parents.

Illinois Master Gardener, University Of Illinois (pdf download)

Creating hybrid varieties is a time-consuming, highly scientific process that may take years of cross-breeding to achieve the desired trait, such as a larger flower or a sweeter fruit. Hybrid plant breeding has existed for hundreds of years. But contrary to what you may have heard, it does not create “Frankenstein” plants. Scientists cannot simply combine the pollen of a red tulip with a white tulip to create a pink one – the laws of genetics aren’t that simple. Scientists carefully choose parent plants with very specific characteristics and attempt to cross-breed them. When and if they succeed, they can become the only source for the seeds of the new variety, referred to as “F1” seeds.

While all heirlooms are open-pollinated, not all open-pollinated plants are heirlooms. Hybrid seed is produced when open pollination occurs between two specific varieties carefully chosen for their superior traits. Such controlled cross-pollination producing hybrid seed results in offspring with desired traits, such as disease resistance, uniformity, and greater vigor. Unlike heirlooms, however, the seed saved from hybrid plants will not grow true to type in the next generation and will be less vigorous and more genetically variable.

Choosing Seeds: Hybrid and Heirloom, University of California Master Gardeners of Butte County

Read more: How To Read A Seed Catalog

Are hybrid seeds worth the extra cost?

Hybrid seeds (F1) sometimes cost more than heirloom seeds, and each gardener must decide if the extra cost is worth the benefit of the claimed trait. You may see great value in disease resistance, insect resistance, or an earlier bloom time, while your neighbor may not. An additional benefit of hybrid seeds is “hybrid vigor,” which refers to their superior vitality compared to heirloom seeds. Typically, more hybrid plants survive the seedling stage and grow larger and more robust than open-pollinated varieties.

Can you save seeds from hybrid (F1) plants?

You can save the seeds from hybrid plants, but they usually do not produce plants identical to the parent. You may be pleasantly surprised or very disappointed by the results. Instead of the traits of the parent plant, the new plants will most likely end up with a random mix of traits of multiple generations of plants used in the breeding process.

Are hybrid plants GMOs?

No. GMOs are created by gene modification in a lab, not in a greenhouse, field, or garden where plant breeders work. A GMO plant is altered by DNA insertion or deletion (turning specific genes off or on through scientific processes). Currently, there are no GMOs available to home gardeners. They are only used in commodity crops such as field corn, canola, sugar beets, alfalfa, soy, and cotton.

Pros and Cons of Heirloom vs Hybrid Plants