Now that we have arrived at the average last date of frost, it is time to go shopping. I wonder what delightful new varieties of annual flowers, vegetables, perennial flowers and shrubs are available this year? Before we go plant shopping, let’s review some plant terminology.
Variety vs. Cultivar: The botanist in me must point out that we commonly use the term variety incorrectly. A variety is a subspecies which is a naturally occurring sub-grouping within a species. Did you know that cabbage and broccoli are the same genus and species, Brassica oleracea, but each is a different naturally occurring variety? The scientific name for broccoli is Brassica oleracea var. Italica, for cabbage it is Brassica oleracea var. capitata, and for cauliflower it is Brassica oleracea var. botrytis.
A cultivar or cultivated variety is a sub-grouping within a species that occurs in cultivation, such as ‘Brandywine’ and ‘Big Boy’ tomato cultivars.
Hybrids: When shopping for plants you may find a plant described as a hybrid. What does this mean? A hybrid results from the cross pollination of two cultivars. This can happen naturally in the garden or controlled by plant breeders. Sometimes a gardener finds a chance hybrid seedling that resulted from cross pollination the previous season between two different parents, such as two summer squash cultivars. While interesting, the fruit of a chance hybrid squash is often not as desirable as the fruit of the two different parent cultivars.
In controlled plant breeding, parent plants with desirable traits are crossed in hopes of getting an offspring with the best of both parents. Offspring that do not “measure up” are discarded. When a hybrid plant with desirable characteristics results, it is maintained in cultivation through cloning or controlled pollination.
However, just because a plant is a hybrid does not mean that it has desirable characteristics for yard or garden use. The hybrid poplars seen in plantations along the Columbia River have been bred to grow very fast so they can be harvested relatively quickly for pulp production. In addition to fast growth, breeders have selected for resistance to certain insects and diseases along with resistance to wind and browsing by deer. They did not select for traits that would make them more suitable shade trees, such as more compact growth, less invasive root systems, or a longer life span.
F1 Hybrids: F1 hybrids are the first generation of plants resulting from a controlled cross between two inbred parent lines. Because of inbreeding, all the plants in an inbred line are extremely genetically uniform. The crossing of these two genetically uniform lines results in offspring that are also very genetically uniform, making them consistent in size, color, and other traits. Additional possible beneficial characteristics of F1 hybrids include increased plant vigor, better germination, and earlier fruit production. However, as with the creation of any hybrid, not all the resulting crosses are winners. Developing F1 hybrids is a tedious, time consuming, and costly process. That is why the F1 hybrids that make it to market are often more expensive than other cultivars.
When it comes to garden veggies, there is a plethora of old and new hybrid tomato, peppers, cabbage, broccoli, cucumbers, melons, summer squash, sweet corn, and carrots cultivars on the market along with lots of hybrid annual flowers, especially petunias and geraniums.
Marianne C. Ophardt is a horticulturist for Washington State University Benton County Extension.