Olcott Arboretum
The Olcott Arboretum is a botanical collection of trees located on the headquarters campus of the Theosophical Society in America in Wheaton, Illinois. Level 1 Accreditation has been conferred by Arbnet, an international community of arboreta. This accreditation confirms that Olcott has identified and marked at least 25 different species of trees. The campus has long been called "Olcott" after a founder of the Theosophical Society, Henry Steel Olcott.
For a map of the trees, see ArborScope, courtesy of Bartlett Tree Experts.
Establishment of the arboretum
In May, 2019, the Theosophical Society received a certificate from the ArbNet Arboretum Accreditation Program, conferring a Level 1 Accreditation effective for five years.
On October 29, 2019, the grand opening of the Olcott Arboretum took place, beginning on the front veranda of the headquarters building. Dr. Barbara Hebert welcomed Wheaton Mayor Phil Suess and Wheaton Parks District Director Mike Benard, and each spoke briefly. Theosophical Society Archivist Janet Kerschner gave a short history of trees on the Olcott campus. Children of the Prairie School of DuPage presented a book of drawings of Olcott trees and birds. The assembled guests then walked around to the south end of the building fora tree-planting ceremony, followed by refreshments in the lobby.
Mayor Phil Suess 
Prairie School children 
Tree planting 
Barbara Hebert and Wheaton officials
History of trees on the Olcott campus
When the Theosophical Society purchased land in Wheaton early in 1925, the first action taken on the bare plowed fields was a plant a grove of trees. The first tree planted, on May 6, 1925, was a silver linden. Members across the United States were excited about the new headquarters estate, and donated money to beautify the land with trees. Each donation of funds for a tree was recognized with a bronze plaque where it was planted. Over the years hundreds of trees, shrubs, and perennial flowers were planted, along with an orchard, grape arbor, and massive vegetable gardens.
Silver linden, May 6, 1925 
Grove on May 8, 1926 
Grove and Rogers Building in 1931
On April 15, 1933, members of Boy Scout Troup 38 worked with Theosophical Society staff in the National Nut Tree Planting Program. They cleared a 6000 square foot nursery bed in the headquarters campus, 15 feet by 400 feet in size, and together planted the 1700 nuts that had been gathered by other Scouts at national landmarks such as the Arlington National Cemetery and Gettysburg battle field. After two years they distributed the saplings to local residents to beautify the town.
Two noteworthy wind events caused significant destruction on the campus. An F1 tornado passed over on August 23, 2007. About 60 trees had to be removed, and 100 were damaged. Then, on July 1, 2012, a straight-line wind storm called a derecho blew east along Geneva Road in a narrow path. Winds of 110-115 mph destroyed 80 trees. Fortunately, no people were injured, and little damage was done to buildings or vehicles.
After each of these storms, members contributed money to replant.
The Olcott Arboretum is working with corporate partners to expand the number of species. On May 4, 2022, fifteen trees donated by Morton Arboretum were planted at the Olcott campus by a crew of staff members and volunteers, after training by Bartlett Tree Experts.