John Caspar Wister was the son of William Rotch and Mary Eustis Wister of the prominent Wister family of Philadelphia. Known as Jack by his family and friends, he spent his youth at the house “Wister” (which stood at Wister and Clarkson Avenues, Germantown, Philadelphia), adjacent to the Belfield estate owned by his grandparents, their descendants, and now by La Salle University. Wister spent much of his childhood exploring his grandparent’s Belfield estate and following the estate’s groundkeeper while he performed his duties. Listening to the groundskeeper stories and learning about his planting techniques left an impact on Wister as he went on to spend his adulthood studying plants.

When the United States entered World War I, Wister enlisted and served in the Advance Ordnance 4 regiment of the American Expeditionary Force, spending most of his time in various ordnance departments and eventually becoming Sergeant of Ordnance in November 1917. Like many others in the American Expeditionary Force, Wister never saw combat, an enemy soldier, or even gunfire during his time in the service. Despite this, as detailed in the letters he sent back home to his loved ones, Wister did not like the army. He believed that its entire structure was full of incompetence and provided the perfect building blocks for communist sentiment. What Wister did like about the Army, however, was the people and the traveling. He enjoyed the roughness of his fellow soldiers and credited them with helping him adjust to life as a soldier. He also enjoyed using his leave time to visit the gardens of Europe and often sent plants back home to his friend Arthur Hoyt Scott, the president of Scott Paper Company and a garden enthusiast. During visits to Paris, Wister became enamored with the horticultural scene and with the help of a French nurseryman was able to have his enlistment ended in France. This unusual circumstance allowed him to travel throughout France and study horticulture.

When he returned to America, Wister continued his horticulture career, spending the next seventy years studying and researching plants and starting numerous horticultural organizations such as the American Iris Society. For his work in the horticultural field, Wister was chosen by Swarthmore College as the first Director of its Arthur Hoyt Scott Horticultural Foundation, and the college later awarded him an honorary Doctor of Science degree. In 1946, he also became Director of the John J. Tyler Arboretum (Lima, PA) and served from 1930-1957 as vice president and then president of the John Bartram Association. The author or editor of a dozen books on horticulture, Wister also wrote over five hundred articles and gave lectures around the country. He was honored by many dozens of horticultural groups, including the New York Botanical Garden, the Horticultural Society of New York, the Royal Horticultural Society of Great Britain, the Pennsylvania Horticultural Society, and the Garden Club of America. At his death in 1982, the Philadelphia Inquirer aptly described John Caspar Wister as “the dean of American horticulturists.”

A native of Montclair, N.J., Gertrude Smith Wister (nee Gertrude McMasters Smith) was born March 24, 1905, the daughter of Stanton and Harriet Briggs Smith. Keenly interested in plant life since her childhood, she attended the University of Wisconsin, where she majored in horticulture and graduated with honors in 1927. After college she worked in a nursery for a short time before starting her own business in garden planning and maintenance in Montclair. In the 1940s she began working during the winter months for the Arthur Hoyt Scott Horticultural Foundation and the Tyler Scott Arboretum of Swarthmore College (then known as the Arthur Hoyt Scott Horticultural Foundation) from 1955 to 1960 while at the same time serving as the assistant director of the Tyler Arboretum in Lima, Pa. From 1975 to 1977 she served as the acting director of the Tyler Arboretum. She remained a loyal and generous supporter of both of these public gardens throughout her lifetime. From 1948 to 1955, Mrs. Wister served as editor of the National Gardener, the bulletin for the National Council of State Garden Clubs. She authored Hardy Garden Bulbs in 1964 and innumerable articles in horticultural publications and magazines. In 1960, she was appointed to the Board of Trustees of the Tyler Arboretum, a position she held for more than 25 years. She was also the assistant editor of the Woman's Home Companion Garden Book in 1947, and she edited the American Daffodil Society Yearbook from 1962 to 1964. Her love of plants and contributions to horticulture won her acclaim and recognition over the years. In 1976 she was awarded the distinguished Achievement Award by the Pennsylvania Horticultural Society, and in 1978 the Massachusetts Horticultural Society awarded her the Thomas Roland Medal for skill in horticulture. In 1982 she received the Gold Medal Award, the American Rhododendron Society's highest honor, for her many horticultural contributions, in particular for cataloging, registering, and perpetuating the Wister hybrid rhododendrons and plants of other hybridizers. In 1985 she received the Scott Garden and Horticultural Award for her national contributions to the science and art of gardening. John and Gertrude met one another while working together at the Arthur Hoyt Scott Horticultural Foundation and were married in 1960.