Choosing the right cultivar for your garden
“The word ‘cultivar’ (short for ‘cultivated variety’) entered the English language in 1923. It applies to plants selected or bred for their desirable traits.”
— David Deardorff & Kathryn Wadsworth, “What’s Wrong with My Vegetable Garden?” (2011)
My interest is always piqued when someone mentions the origin of English words, particularly garden-related vocabulary. I delved further into the etymology of “cultivar” to learn that it was coined by renowned American horticulturalist Liberty Hyde Bailey (1858-1954) who first used the term in the article “Cucurbita Cultivars” published in the “Cyclopedia of American Horticulture” (1900), of which he was editor and primary contributor.
Bailey went on to publish a scientific journal called “Gentes Herbarum” (“Kinds of Plants”) in 1920, which, similar to Deardorff and Wadsworth’s book, provided profiles of individual plants and plant genera, as well as (then) updated nomenclature. In 1930, Bailey published “Hortus,” a guide to cultivated plants in North America.
Bailey had long experience with plant cultivars. When he was 10, he learned from his father how to top-graft apple trees and supposedly had one tree with 40 different varieties. Certainly, he would have agreed with Deardorff and Wadsworth’s advice for gardeners to choose cultivars that will thrive with the growing conditions in their garden.
According to Deardorff and Wadsworth, “If you live in a short, cool growing season, then you need to select cultivars with the shortest days to maturity.” In our area, short-season cultivars are good choices for some warm season crops such as melons, eggplant and tomatoes. Cultivars that are quick to mature are also good for spring planting cool-season crops in our area, particularly lettuce, spinach and peas. Slow-bolting cool-season cultivars are also good choices.
A few examples of early maturing cultivars include ‘Yellow Moonbeam’ watermelon, ‘NY’ slicing cucumber and ‘Crimson Sprinter’ tomatoes. ‘Sugar Ann’ bush peas produce about 10 days earlier than other snap peas. ‘Popeye’ spinach is one example of a cultivar that has been bred to last longer in warmer weather.
In addition to cultivars that reach maturity faster or are slow to bolt, other cultivars have been bred for resistance against diseases or insect pests. Look for capital letters on plant labels that indicate which resistance has been bred into the plant. For example, TMV means the plant is resistant to tobacco mosaic virus, F means it’s resistant to fusarium, V to verticillium wilt, and PM to powdery mildew.
How is a plant bred for early maturity, pest resistance or other desirable traits? Using traditional plant breeding methods (not genetic modification methods), new varieties are developed by combining qualities from two closely related plants through selective breeding. Pollen that contains the genes for a desired trait is transferred from plants of one crop variety to the flowers of another variety with other desirable traits. Eventually, through careful selection of offspring, the desired trait will appear in a new variety of plants.
Genetic modification, on the other hand, involves combining genes from unrelated organisms and bypassing sexual reproduction to produce the offspring.
Some cultivars are labeled F1 hybrids, which stands for “first filial” generation — this plant is the initial cross between its two parent plants. All F1 seedlings are highly uniform and will grow faster and bigger and producer better fruit. On the other hand, second-generation seedlings from F1 plants will not have the desired uniform traits like their parents.
F2 hybrids are produced by crossing four genetic lines, rather than two lines. Again, the hybrids are uniform, vigorous and high yielding, but they do not grow “true to type” from seed in the second or succeeding generations.
Whereas F1 and F2 hybrids are cross-pollinated through human manipulation, open-pollinated cultivars are developed by selecting seedlings with specific desirable traits and allowing them to cross-pollinate freely among themselves. Open-pollinated varieties always come true from seed, which means gardeners can save their own seed and continue growing the same plants.
Heirloom cultivars are always open-pollinated and have been developed over several generations. Many heirlooms are “land races,” which means they were developed in a specific place by a specific group of farmers. Heirloom seeds will grow true to type as long as the parent plants were not cross-pollinated by a different variety.
Deardorff and Wadsworth also discuss patented cultivars. Genetically modified plants with patents may not be propagated in any way; however, the authors say “plants that are produced by traditional breeding programs may always be lawfully propagated, no matter what the tag says.” They add that gardeners may propagate a patented plant from seeds, divisions or cuttings for personal use, but may not sell plants that were propagated from a patented plant.
Liberty Hyde Bailey spent a lifetime collecting, chronicling and breeding plant cultivars; however, he also published a book of poetry called “Wind and Weather” in 1916. A poem called “Miracle” depicts Bailey as a nature enthusiast as well as a scientist:
“Yesterday the twig was brown and bare;
Today the glint of green is there.
Tomorrow will be leaflets spare;
I know nothing so wondrous fair,
No miracle so strangely rare.
I wonder what will next be there!“
Rhonda Nowak is a Rogue Valley gardener, educator and writer. Email her at Rnowak39@gmail.com. For more about gardening, check out her podcasts and videos at https://mailtribune.com/podcasts/the-literary-gardener.
My garden to-do list this week
Pinch back basil, pepper and eggplant tips when plants are 6-7 inches tall to promote branching.
Add several inches of mulch to potato grow bags to prevent sunlight from reaching tubers and turning them green.
OSU recommends applying a foliar feed to cantaloupes when they begin to vine to enhance sweetness: 1 teaspoon household borax and 1 tablespoon Epsom salts added to 1 gallon water increases boron and magnesium.
When pepper plants begin to flower, apply a foliar spray to increase crispness and sweetness: 4 tablespoons Epsom salts added to one gallon water.
Make sure to spend time relaxing and enjoying the garden before it gets hot — maybe write a poem.