USDA Botanist Was Breeding The World’s Finest Hemp

Japanese hemp grown in a field at the Agricultural experiment station, Lexington, Kentucky 1901

In the dwindling days just before America’s cannabis prohibition, Uncle Sam not only grew hemp but also sought to breed the world’s best hybrids.

HANDOUT PHOTO: (original caption on photo) Lyster H. Dewey, with a scoop devised for taking up /”threshing” hemp seed from individual selections beaten out on canvas, Office, November 1929. (Courtesy of Adam Eidinger/ Hemp Industries Association) StaffPhoto imported to Merlin on Mon May 10 20:11:09 2010

At the dawn of the 20th century, the United States started an extensive hemp breeding program under the U.S. Department of Agriculture. The government project was overseen by a botanist working for the USDA, Lyster Dewey.

The project became Dewey’s passion. Although Dewey had many plants in his research garden, one variety always stuck out to him: hemp.

Dewey began much like cannabis growers do to this day, by sourcing the best seeds from around the world. He had a special interest in Asian lines, believing “the tallest and best hemp plants are produced in China and Japan,” he wrote in the 1901 FDA Yearbook and later repeated in 1903. By which time Dewey had amassed a collection of breeding stock from Russia, Italy, Hungary, Japan, and China, along with full access to domestic seed.

Dewey grew and bred his experimental hemp right where the Pentagon currently sits, originally known as Arlington Farms. After breeding his exotic genetics, Dewey would test his creations by sending his seeds to the government-partnered Experiment Agricultural Stations throughout the United States — a testing practice still followed by many cannabis breeders today.

“In the spring of 1901, seed of several varieties of Japanese hemp were imported through the Office of Seed and Plant Introduction, and they are now being grown in the testing garden and at six other stations. Some of them give promise of much value.”

unidentified man beating out seed from Japanese hemp plants grown on the Agricultural experiment station, Lexington, Kentucky 1901

Taking the foreign-sourced seed, Dewey bred the best examples of each line, sometimes adding domestic varieties to create new hybrid hemp seeds.

After breeding hemp for more than a decade, Dewey had his methods down to a science, declaring his “methods of hemp selection devised in 1913 have been followed since with only slight modifications” in the 1927 USDA Yearbook.

Dewey created many new exotic hybrids in his experimental Arlington garden, bringing the world’s best genetics together on American soil. Out of his many creations, he proudly published four of his favorite hybrids in the 1927 USDA Yearbook.


The variety called Kymington (Kentucky-Minnesota-Washington, from the origin of the seed and places of development) is a result of successive individual selections from the progeny of the best single plant of Minnesota No. 8, grown in 1912. This mother plant was 10 feet, 6 inches tall. The 311 plants in the initial plot of 1914, on clay loam upland at the Arlington Experiment Farm, averaged 9 feet, 11 1/2 inches tall. Each plant selected to furnish seed for the following year was taller than the mother plant of 1912. The average length of internodes in this initial plot was 4.37 inches. These measurements increased until 1923, when the average height was 16 feet, 9 1/4 inches and the average length of internodes was 5.94 inches. Since 1923, the measurements have declined somewhat, due in part to unfavorable soils and seasons. But in all instances, the average measurements have been above those of the original plot, and in 1927 they were slightly better than in 1926.

This variety has been grown extensively by Kentucky hempseed growers, some of whom have kept the seed pure.


The Chington (China-Washington) variety has been developed by successive individual selections from the progeny of a single plant in 1913. The seed was received from Hankow, China, through the Office of Foreign Plant Introduction, and given the S.P.I. No. 35251. It was planted in the testing garden, and unlike most of the numerous introductions of hempseed, it gave promise of value. It averaged 5 feet, 11 inches in height, and the best single plant from which seed was saved was 10 feet, 6 inches tall. Seed from this best plant was sown at the Arlington farm in 1914, and the annual selection has been continued. This strain also reached its greatest development in 1923, when it averaged 16 feet, 8 inches in height, with internodes averaging 6 1/2 inches. A few plants attained a height of 20 feet. Since 1923, the measurements have declined a little, though remaining always above those of the mother plant of 1913 and the average of the initial plot of 1914. With the slight reduction there is greater uniformity.

The Chington variety has been grown extensively by hempseed growers in Kentucky, and in some instances efforts have been made to keep it pure. Large fields of fiber hemp sown with pure Chington seed are remarkably uniform and give good yields of excellent uniform fiber.


The Ferramington variety has been developed by successive selection from the progeny of a cross made in 1916. In that year a row of Ferrara, the best hemp of northern Italy, was grown in the plot of Kymington, and all of the Ferrara staminate plants were removed before they shed any pollen. Seed from the best Ferrara plants was saved, and this has been grown and selected at the experiment station at Madison, Wisconsin. The cross was made for the purpose of combining the earliness and smaller diameter of stalks of the Italian hemp with the greater height and longer internodes of Kymington. This result has been achieved after many years of selection to eliminate diverse types from the progeny of the cross.

This Ferramington has been tried in Wisconsin, where it gave a very good crop nearly two weeks earlier than the main hemp harvest. It has also been tried near Bologna, Italy, where it produced fiber fully equal in quality to that of the Ferrara hemp grown in the same field, and about 1 foot longer.


The Arlington variety is being developed by successive selection of individual plants from the progeny of a cross made in 1919 between Kymington as a pistillate parent and Chington as the staminate parent. It shows increased vigor both in growth and in production of seed, and the stalks are slender and more elastic than those of any of the other varieties. It is a little earlier than either of the parent varieties, both of which are later than most of the hemp from unselected Kentucky seed.”

Dewey standing with ‘Kymington hemp and original stock’ at Arlington Farms, Virginia October 22, 1919.

Three decades of breeding the world’s best genetics Dewey came to one conclusion, “varieties of improved type are a result of selection,” he wrote in the 1927 Department of Agriculture Yearbook. In a nutshell, breeding the best traits results in improved plants.

Dewey’s breeding program for the United States continued into the 1930s when he would be forced to defend hemp from the looming cannabis prohibition. In a bitter twist of fate at the end of his career, choice was taken away and the program was ultimately shut down, ending Uncle Sam’s attempt at breeding the world’s greatest hemp.

Kymington hemp plant, named for the origin of the seed Kentucky-Minnesota-Washington, grown at Arlington Farm, Virginia 1914

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